Drive letter problems

Discussion in 'Acronis True Image Product Line' started by laserfan, Jun 9, 2008.

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  1. laserfan

    laserfan Registered Member

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    Over in this thread is a discussion about problems with restoring partitions, which includes this statement by (very helpful) member k0lo:

    I'm still not exactly sure I understand the "simple to avoid this" part, but at least am pleased that (owing to this board) I seem to have solved an issue with my XP-based P4 PC that's been a workhorse since about 4 years ago now.

    For several months I've been experiencing odd BSOD problems among which appeared PAGE_FAULT_IN_NONPAGED_AREA. What's been odd to me is that this PC has almost never failed in actual use, i.e. I can run complex processes and test programs on it that take days to run and it just runs perfect. Only when I shut-down or re-boot or enter-or-leave a sleep state would I get a BSOD. So it's been annoying/disturbing to me, but not a "killer" problem, ya know?

    But having recently experienced an issue where TI (v7 in my case) didn't want to restore a .tib to my hdd, giving a message like "you can't restore an image to the same drive, you dummy" (I added that last part) I started looking into this question of "drive letter problems" that I've been reading about here on the Wilders board. Well, to make a long story longer, I've used this PC for years, swapping drives in-and-out and using more recently one of those USB-to-IDE/SATA converters also, and I discovered that my HKLM\System\MountedDevices key had 170 entries in it! Thinking that might be confusing Windows some times (d'ya think?) I deleted the key and re-booted and now have a more reasonable 16 entries (I have 4 ides and a SATA and three or four USB gizmos I plug-in occasionally).

    Another thing I realized (I think anyway that this has been my BSOD problem) is that I've had my main PageFile set-up on my E: drive, a 2nd physical hdd from the C:\System drive that of course has XP on it. Here's the problem though: I HAD CHANGED THE DRIVE LETTER OF THIS DRIVE TO E: MANUALLY, USING WINDOWS DISK MANAGER. I did this because, being the anal person that I am, I wanted the 2nd (logical) partition on my Drive 0 to be D: and my 2nd Hard Disk w/a single Primary partition to be E:. But now I've found that the algorithm Windows uses to assign letters naturally goes like this:

    Primary partition (startup) gets C:
    Next Primary gets D:
    Next Logical gets E:
    etc.

    Well, my drive 0 had been set by me to have the 2nd partition set as D: and the drive 1 primary partition set as E: which is bass-ackwards from what Windows would normally assign/expect. So I now BELIEVE that Windows got confused sometimes when it went looking for my paging file, expecting it on E: but instead of finding it on my Drive 1 was looking for it on Drive 0 1st Logical partition ("natural E:"). I've changed my setup to now go with the natural algorithm and haven't had a BSOD since.

    I hope k0lo finds this thread and offers his explanation of "simple to avoid drive letter problems" cuz altho I've gotten alot smarter lately about this stuff I'm still not sure what that comment refers to specifically.

    I'd be curious too if others here have a monstrous MountedDevices key in the computer they've used to make backups. I think mine was confusing Windows no end. Sorry for the long post but I just had to get this off my chest!:p
     
  2. K0LO

    K0LO Registered Member

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    laserfan:

    It's by luck that I saw your post. Yes, on my 16-month old Vista installation there are 49 entries in the MountedDevices key in the registry. After a few years and many pluggings and unpluggings of USB keys this list might grow to be huge, so some housekeeping may be in order.

    Just be aware that if you delete the entire key then Windows will automatically rebuild it on the next boot and your disk drive letters will come out the way Windows thinks they should be. For 99% of users this will probably be correct but for the oddball setups (like yours truly has), it might result in the wrong drive letter being assigned to the system partition. Then you will need to get into the registry and make the desired assignments or force the issue by hiding a partition or two until Windows gets it right.

    What I was referring to in the other post was the heirarchy used by Windows when assigning drive letters. In other words, just how does Windows assign drive letters? My "simple explanation" is that you take a few minutes to understand this heirarchy so that you know what to expect Windows to do. Once understood, the rest is easy. The first reference below gives a fairly concise summary of the heirarchy.

    Here is the oldest reference on the subject but still applicable today, even for Vista.
    Here is a newer reference for Windows 2000 that adds additional info about dynamic volumes.
    And here is a procedure that you can use to fix an incorrect drive letter assignment on your system volume. One way to do this if need be is to boot from BartPE or VistaPE and use the registry editor. Alternatively you can remove the disk and temporarily install it in another PC, and then "mount" the HKEY_LOCAL_MACHINE registry hive of the disk from regedit on the other PC and then edit the registry from there.

    Finally, I think that you are correct about the paging file location being your BSOD issue. An easy fix for that is to remove the paging file, reboot, and then enable a paging file on the desired drive/partition.

    Hope this helps...
     
  3. laserfan

    laserfan Registered Member

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    No, I tried that. Again, I believe the problem was that because I'd swapped the drive letter designations away from what Windows-on-boot expects them to be, it couldn't find my paging file in the location expected. Indeed, what clued me-in to the problem was when I noticed a paging file on a disk where I'd never assigned one--I do know for example it's useless to place a paging file on a logical partition of the same drive as C:. So I didn't know where the pagefile.sys came from--I didn't create it--I believe Windows said "I expect one here so I'm gonna make one".

    I know now too the algorithm you linked to. What I DON'T understand yet is why TI can get confused when asked to restore a .tib ("you can't restore to the same drive" above). I was not TRYING to restore to the same drive, but TI thought I was somehow...

    I know, I'm not being very clear--next time I encounter this I will do a better job of documenting my steps and the exact dialog, tho as I said too I'm using TI7 and it's not supported anymore so I've never expected help from Acronis.

    P.S. A REAL MYSTERY in all this is why MS allows the end-user to change these drive letter designations to be inconsistent with its algorithm.
     
  4. K0LO

    K0LO Registered Member

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    I'm going to hazard a wild guess here, but I think that both of your problems (with the paging file and the TI location to restore to) were caused by confusion in the MountedDevices registry key. In this key the drive letter assignments are stored by GUID (Globally unique identifier; those 24-character strings of hex digits). If you change a drive letter the GUID will not change. If you swap disk positions around the GUID will not change. So I'm guessing in your case that something got confused or perhaps you somehow ended up with duplicate entries in the registry.

    I note from your first post that all of the problems went away after clearing this key and letting Windows regenerate it. So maybe that was the reason you got things fixed up?

    The reason that Windows lets you change drive letters is for convenience and personal preference. Internally disk partitions are located by GUID (especially in the later versions of Windows; I'm not sure about pre-XP versions). The way that this system is supposed to work is that, as each drive letter is assigned or chosen, it is stored in the registry. When Windows is booting it looks at the HKEY_Local_Machine\System\MountedDevices key in the registry to see if there are any drive letter reservations. If so and if a partition with matching GUID is found at boot time, then the reserved drive letter is reassigned. If not, a drive letter is assigned according to the Windows drive letter heirarchy. This continues until all disks/partitions are mounted.

    What can get you in trouble with some TI restores is when a partition is restored to a different location on the disk. Then the GUID of the partition changes and the reserved drive letter in the registry is no longer applicable, so Windows assigns a new drive letter. Hopefully the letter that gets assigned is one that makes sense.
     
    Last edited: Jun 9, 2008
  5. laserfan

    laserfan Registered Member

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    Many thanks for your excellent description above.

    I suspect that you are exactly right about that key being the source of the TI problem, because indeed over the course of the last several months (with the random BSODs) I have along-the-way pulled-and-moved-and-swapped-and-you-name-it with these drives because I'd been concerned I was experiencing a drive failure. Now from your explanation I can see that there's no way Windows couldn't be confused, particularly given my 170 entries, since I've never owned 170 drives and so the drives I HAVE attached had been entered in there a number of times for all the permutations I'd ever attempted.

    Thanks again Mark, your posts have been most helpful! :thumb:
     
  6. Howard Kaikow

    Howard Kaikow Registered Member

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    It depends.

    Sometines deleting the MountedDEvices key can lead to untold grief.
    Once, I had to restore a partition from backup after deleting that key.

    Not to mention, depending on the OS, that key is out of sync with the actual assigned drive letters.

    If one understands how, I would recommend that the ONLY keys that should be deleted are those that display redundant drive letters.
     
  7. laserfan

    laserfan Registered Member

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    You did, of course, export a backup before deleting the key?

    "If one understands how" is saying a mouthful. I have looked at my backup of my old MountedDevices key, with its 170-some entries, and certainly wouldn't be comfortable editing ANY of it.

    I think if one has dozens/hundreds of MountedDevices in there, and mysterious problems as I did, make a backup, then delete the damn thing and reboot!
     
  8. Howard Kaikow

    Howard Kaikow Registered Member

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    Backing up the key is insufficient. One needs a backup of the OS, as one might not be able to reboot if th MountedDevices key is deleted or improperly edited.

    How to edit that key in very specific circumstances is well covered in KB articles, in particular for the case of USB drive letters getting messed up.
    Other than editing cases specifically described by th KB, it should be hands off.

    Forthe last time, backing up the key may not be sufficient as one might not be able to reboot, and arbitrarily replacing the key may not always work.
     
  9. jonyjoe81

    jonyjoe81 Registered Member

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    I ran tests deleting the "mounted devices" drive letter entries (windows xp pro) numerous times, and never encountered any problems. The harddrive always booted up with no problem. I've never encountered a "mounted devices drive letter" problem on any of the restores that I have performed. I would consider that a rare event (probably will only occur if the system drive letter was something other than the default c: drive).

    All of the problems I've encountered are related to the "partition ID drive letter" that is the one that gets changed around during restoration of windows xp. That's why a win98 floppy or deleting all the "mounted devices" drive letters won't fix a non-booting restored drive that has a "partition ID" drive letter problem (tested and certified by me not to work). On the other hand if you have the ability to modify the "partition ID" drive letter, then you can fix a non-booting restored drive everytime.

    Before I use to think that the "mounted device" drive letter was the cause of all my problems, but through research I found out about the "partition ID" drive letter. Both of these drive letters must match in order for hard drive to have a successful boot.

    This only applys to windows xp/w2K/server2003 operating systems, windows vista doesn't have any drive letter problems that I know of.

    https://www.wilderssecurity.com/showthread.php?t=210322
     
    Last edited: Jun 10, 2008
  10. laserfan

    laserfan Registered Member

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    But I never said "replacing the key will always work" and of course I DIDN'T replace the key; Windows did, i.e. rebuilt it as it was supposed to. I only said "I think mine (my 170-entry key) was confusing Windows no end." CERTAINLY I made a complete True Image backup of my system before making these changes (not only deleting the MountedDevices entries but also changing drive letter designations), including as well a System Restore point and exporting the MountedDevices registry key for safekeeping and later comparison.

    Lest anyone read this thread and be unclear about this: Always make-and-verify that you have a working backup of your system on-the-shelf before attempting Windows Registry modifications!

    @jonyjoe81 -- I too did my research wrt MountedDevices and, despite what Howard here insists, could not find any evidence that it was even dangerous to do, much less could irretrievably trash one's PC. And thanks BTW--several of your posts gave me clues to this, the solution to a long-standing mystery with this PC.
     
  11. MudCrab

    MudCrab Imaging Specialist

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    In most cases, clearing the MountedDevices Registry entry should not cause any problems. Windows will recreate it when it boots. Also, when Windows is installed it has to create these keys. As long as the Windows partition is assigned C: and the Windows partition is the Active partition, this procedure should work. You may have to manually change any other partition letters if they are not correct. If you have any programs installed on other partitions that are required for Windows to boot, problems will probably occur if that drive letter changes. However, on most systems, this is not a concern.

    In using your much pushed justboot corrector (or similar tools), you are “fixing” your MountedDevices drive letter problems. This is the only way it can be fixed since the program isn’t going to “move” the partition and change the Disk ID so that the Partition Signature matches the original.

    What you are calling the Partition ID Drive Letter is not a drive letter, but the Partition Signature. It is created using the Disk ID and a calculation from the partition’s starting offset.

    Excerpts from Dan Goodell’s site:
    1. Windows NT, 2000 and XP keep a list of partitions, identifying each by a signature. The list is maintained in the registry key [HKEY_LOCAL_MACHINE\System\MountedDevices]. Drive letters are also recorded in this registry key and matched to the corresponding partition signatures.
    2. The partition signature is derived from the DiskID and the partition's starting sector number. The DiskID (sometimes called the "NT serial number") is a group of four bytes in the master boot sector (LBA 0) at location 01B8h. Each partition's starting sector number is doubled and combined with the DiskID to form a unique signature for that partition.
    3. Every time Windows boots it calculates signatures for all partitions and adds any new signatures to the [MountedDevices] registry key. If the partition's file system is recognizable to Windows (i.e., unhidden FAT/FAT32 or NTFS), a drive letter is also assigned. Drive letters previously assigned are remembered and skipped when Windows assigns letters to newly discovered partitions.

    This value is saved in the Windows Registry in the MountedDevices key. Clearing the Disk ID from the drive or clearing the MountedDevices key will force Windows to reset these values and force reassignment of drive letters when Windows boots. Depending on how the system is setup, this may or may not result in a bootable system. However, any problems that cause a non-bootable system due to the incorrect assignment of drive letters by Windows are not a different problem as you make it sound. It is still exactly the same problem. Using two different terms and treating Partition Signatures and MountedDevices entries as separate entities is just going to cause confusion. They are not; both are part of a single entry in the Registry for each partition.

    It would be nice if you would substantiate your claim that this doesn’t work by posting your test results along with the procedures used. Using the Windows 98 MBR reset or clearing the MountedDevices key will force Windows to reassign drive letters. If there are other settings that are not correct (wrong partition Active, Windows partition not originally C:, etc.), the reassignment may not result in the desired outcome.

    You have previously posted that you have no desire to get to the root of the problem as you prefer to just fix it after it has occurred: “the cause of the problem is unimportant, I only care about ‘how to fix the problem’”. You have also posted that you “blame everything on drive letters”. This is not the kind of advice that should be given out. People come here looking for help and our advice should be as accurate as possible and aimed at solving their problem, not possibly creating other problems. The correct solution is to find out what is causing the repeated failure on a system and then find the steps necessary to avoid it. The drive letter problem is one that can be avoided under normal circumstances and certainly shouldn’t be considered normal to happen repeatedly unless something is being repeatedly done incorrectly.

    As stated above, there is no such thing as a Partition ID Drive Letter. There is only the Partition Signature and it’s stored in the Registry. The Signatures have to match, not the drive letters. That is to say, the Partition Signature calculated by Windows for the partition must match the Signature saved in the MountedDevices key for Windows to reassign it the same drive letter.

    The exact same problems can and do happen with Vista.

    ---

    Below is a sample of what the MountedDevices key shows. As you can see, the Drive Letters are assigned based on the Partition Signature. This value is calculated from the Disk ID and the partition’s starting sector offset. (In the picture below, C:, D: and E: are on one drive and F: is on another.) When you use programs to “fix” the drive letter by editing the Registry, the Partition Signature is being changed (or added) to match the correct value as currently calculated from the disk (or drive letters are being shuffled, which amounts to the same thing).

    Drive_Letters_and_ID_Values.jpg
     
  12. jonyjoe81

    jonyjoe81 Registered Member

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    If you can suggest another program that can modify the "partition signature" (aka "partition ID drive letter"), I can run some tests and possibly find a substitue for a "boot corrector". The "boot corrector" works great and I think of it highly, but many people might not be able to afford one. If there is a way of "modifying the "partition signature" with freeware I think that can be quite useful.
     
  13. Brian K

    Brian K Imaging Specialist

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    If you want to correct a system drive letter back to C: (and that's the majority of cases) just use fdisk /mbr from a Win 98 floppy. Or the Acronis xfdisk CD.

    For people who like making life difficult for themselves by not using C: as their system drive letter, they can use this BartPE plugin. RegistryEditorPE.

    I made this comment about using the plugin...

     
  14. K0LO

    K0LO Registered Member

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    Usually you don't need to modify the partition signature; Windows will calculate the signature for each partition that contains a Windows-compatible file system at boot time. These signatures will be ready and waiting in the registry. All you need to do is to make sure that each key has the desired drive letter associated with the signature. 99% of the time they will be correct. For any incorrect keys, rename them.

    Tools that can do this are regedit.exe on any Windows PC or on BartPE or on VistaPE or on the Vista DVD.

    Better yet, plan ahead so that the drive letters come out correct the first time. 99% of Windows users won't even have to think about this because it will "just work". The other 1% are people who dual-boot two versions of Windows the "Microsoft Way" or have unorthodox installations. I have one of those but with a little forethought I completely avoid the issue.
     
  15. jonyjoe81

    jonyjoe81 Registered Member

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    I think everyone (except me) is still confused by the drive letters. There are 2 that must match for the computer to boot. "mounted devices" and "partition ID". All my tests have proven that. A Win98 boot floppy or regediit can fix a "mounted devices" drive letter, the only thing that can fix a "partition ID" drive letter is a "boot corrector". The utility "savepart" will show you both of these drive letters. I'll keep looking for other programs that might be able to do what a "boot corrector" can do.
    If people rely on the "mounted device" drive letter to diagnose a drive letter problem, more than likely they will end up with a wrong conclusion. I've seen too many people disregard an obvious "drive letter" problem and end up never getting the "restored drive" to boot.
     
  16. K0LO

    K0LO Registered Member

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    I think the rest of us have come to a completely different conclusion and that the confusion may lie within yourself. We have all been trying to tell you that you have several misconceptions about the "drive letter problem" and, as a result, are posting inaccurate and misleading information that may get someone into trouble.

    There are not two sets of drive letters. Perhaps this is semantics but if you look at MudCrab's picture above you can see that for each partition entry in the registry there is a) a DOS drive letter associated with b) a partition signature. This in one entry in the registry for each Windows-compatible partition on the disk. Think of it as "name" and "address" if you will. Of course they have to be properly matched up to be correct entries, but if they are not then you can fix either the "name" or the "address" to correct things.

    Despite what you are claiming, a boot corrector is not needed; regedit can fix up mismatched entries. Let's take an example:
    Code:
    \DosDevices\C:     67 14 68 14 00 7e 00 00 00 00 00 00
    \DosDevices\D:     67 14 68 14 00 4a 2a 00 0a 00 00 00
    This is from my Vista machine's disk with the proper entries in HKLM\System\MountedDevices for the two partitions. C is the Vista System partition and D is a data partition. Now, let's assume that I've restored an image of this to a new disk, so there will be a new disk ID generated by Windows, and let's further assume that Windows gets it backwards on the first boot and the two drive letters, C and D, get swapped. The registry may then look like this:
    Code:
    \DosDevices\C:     [COLOR="green"]bf a5 c0 a5[/COLOR] [COLOR="blue"]00 4a 2a 00 0a 00 00 00[/COLOR]
    \DosDevices\D:     [COLOR="green"]bf a5 c0 a5 [/COLOR][COLOR="blue"]00 7e 00 00 00 00 00 00[/COLOR]
    Here, C and D are swapped and there is a new disk ID (the first 4 bytes [in green] of the partition signature are now bf a5 c0 a5 instead of 67 14 68 14). All that you need to do to fix this is to edit the registry key names; swapping "C" with "D". The two partition offsets [in blue] are correct because Windows calculates these on first boot and they are sitting there in the registry waiting for you. So after changing the key names you would have this:
    Code:
    \DosDevices\[COLOR="Red"]D:[/COLOR]     [COLOR="Green"]bf a5 c0 a5 [/COLOR][COLOR="blue"]00 4a 2a 00 0a 00 00 00[/COLOR]
    \DosDevices\[COLOR="Red"]C:[/COLOR]     [COLOR="green"]bf a5 c0 a5 [/COLOR][COLOR="Blue"]00 7e 00 00 00 00 00 00[/COLOR]
    And this would fix the problem. Or, if you don't want to swap the key names (substituting C for D and vice-versa) instead you could copy and paste the partition signatures to fix this. In either case, once you have matched the correct drive letter to the corresponding partition signature, you have fixed the problem.

    Just to further demonstrate that a "boot corrector" is not needed, you could also calculate the partition signature by hand and enter it in the registry key. It isn't a very difficult calculation; it's just the 4-byte disk ID followed by the offset in bytes from the start of the disk, which you can determine from the partition table in sector 0. But why bother? Windows makes this calculation for you when it boots.

    Finally, you don't have to believe any of us here. One of the recognized authorities on the PC boot process, partitioning, cloning, and imaging is Dan Goodell. Here is a link to his article on fixing drive letters. Please take the time to read it, and re-read it. It's a very well-written article from a recognized expert on the subject and you should find that it will clear up some of your misconceptions.
     
    Last edited: Jun 13, 2008
  17. laserfan

    laserfan Registered Member

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    An interesting discussion/distraction folks, but for the record I didn't have a boot problem at all. I had some difficulty convincing ATI that the drive I wanted to restore TO was NOT the same drive I was restoring FROM. I also was experiencing occasional BSODs which caused me to think I'd done wrong by my PC for trying to put a paging file on a 2nd hard drive (for speed/efficiency purposes). So I suspected "drive letter problems".

    After finding the MountedDevices key and observing that it had 170 entries, I let XP rebuild it and my problems have not reappeared. I've looked at my problematic saved Registry key and of course 170 entries are ugly to wade thru indeed--all I found for certain is that I had 3 Volume entries for two drive partitions C: and D:. Maybe if I ever encounter this again I'll be smart enough to ID which entry was the "odd man out", but deleting all key entries and rebooting was easy enough so I'd probably do that again.

    I did, along the way, run the justboot boot corrector demo which purportedly would have told me if I had a problem it could fix, and it didn't reveal anything was amiss. So for lack of a better term I would say only that the one-trick pony approach doesn't work to solve all "drive letter problems".

    Incidentally, it WAS the Goodell site that inspired me to focus on my MountedDevices key--excellent info there.
     
  18. GroverH

    GroverH Registered Member

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    Thanks to MudCrab and k0lo for taking the time to use examples and explain more about Partition signatures and MountedDevices. For those interested, it certainly helps us to better understand what can go wrong and how to fix issues of this type.

    laserfan,
    Just an FYI: I have 152 entries in my mounted devices without any adverse effects--that I am aware of.

    I have 4 drives using 13 drive letters and 3 CD/DVD drives using 3 letters.
    Except for drive C system drive, none of the drives are assigned the drive letters originally assigned by Windows. All drives use consecutive drive letters and the DVD drives are assigned drive letters after all the others.
    disk 1 = c ,d ,e
    disk 2 = f, g, h
    disk 3 = i, j, k
    disk 4 = l, m. n, o
    cd/DVD drives = p,q,r​
    My USB (acronis) bootable drives (when inserted) have been pre-assigned drive letters such X_Y_Z.
    My flash drives (when inserted) assume whatever drive letters are available at the time of insertion.

    As a result of this thread, I did delete my MountedDevices. The number of entries was reduced to about 20 or so (I did not count). However,
    Windows then re-lettered(changed) all my drives to its own protocol which differed from what I wanted. I then was forced to re-letter the drives back to my original choice which added approximately 20 more entries to the MountedDevices. Since I had my page file on drive "O", it would not let me re-letter that drive until I moved the page file back to drive C (temporarily).

    Then, I restored my system partition and put the system back to the 152 entries as I had other tests I wanted to perform. I think the reason I had so many entries is that in times past, I had done several drive letter re-assignments until I had what I wanted. Some time in the future, I will probably delete the MountedDevices again and work from fewer entries. A nice little test which adds to ones experiences!
     
    Last edited: Jun 14, 2008
  19. laserfan

    laserfan Registered Member

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    You're a brave soul--unless my PC's broken I'm disinclined to try to fix it! :D
    Sure, in my case I had 170 entries but only one (I think) that was actually causing a problem! ;)

    You no doubt have done a lot of swapping drives in, out, and around. In my case my C: partition originated many years back and not only has been upsized a few times (thanks to Acronis) but I've also used this PC to repair & test so many *other* PCs & situations I couldn't possibly list them all.

    But apparently it only took one stinker (key) to make Windows puke, though frankly it barfed so seldom that I've sorta developed a new respect for Windoze--for all the abuse I dish-out it actually has worked pretty well for me (XP that is, tho I did like 2000 pretty well also).

    Thanks for your post.
     
  20. Xpilot

    Xpilot Registered Member

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    How exactly does one clear the mounted devices folder or in my case two folders?
    I have not done a count but there is page after page of them. Probably getting on for a thousand entries.
    I deleted both folders and on re-boot the computer played the catchy opening bars again and again with a nice blue screen and a somewhat shrunken Windows logo.

    Because my backup method is based on swapping over restored hard drives I can understand that many entries are generated over the years but it seems a bit untidy to let the lists grow and grow.

    BTW recovery to normal just entailed swapping the main drive for one I made earlier. So I am able to try most things in a risk free manner.

    Xpilot
     
  21. laserfan

    laserfan Registered Member

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    We are talking here about a REGISTRY KEY, not a "folder". And if you've misspoken, and meant "key" there is no way you can have two named exactly the same in one location...?
     
  22. Xpilot

    Xpilot Registered Member

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    In Reg edit, cimbing down the tree HKEY local machine- system- mounted devices I find two folder icons, one is called mounted devices 1 and the other mounted devices. Opening either one shows many hundreds of entries only the last ten or so refer to Dos devices with drive letters.
    Does this make any sense to you?

    Xpilot
     
  23. MudCrab

    MudCrab Imaging Specialist

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    Xpilot,

    I've seen that before. I would try just making changes to the standard MountedDevices key. Also, I would recommend that you only delete the unused values since you're just "cleaning" and not trying to fix a problem. For example, leave your C:, D:, E:, etc. and whatever partitions are always assigned.

    If you wanted to play with the other key, you could export it so you have a backup (if you cared) and then remove it.
     
  24. Howard Kaikow

    Howard Kaikow Registered Member

    Joined:
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    2,802
    Both keys should be present.
    I ASSuME that 1 is a backup for the other.

    MSFT has KB articles on editing MountedDevives, in particular due to a bug with USB drives that sometimes makes them appear more than once with different drive letters, or even changed drive letters.

    AT most you should only edit the lines that specify the d.rive letters to eliminate particular ones, or to change a drive letter
     
  25. JustAnotherNoob

    JustAnotherNoob Registered Member

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    Location:
    Belgium
    The tread title " Drive letter problems" sounded all too familiar ... I too have struggled with this in the past, as Mark might remember. I do agree however, that "Once you figure out how Windows assigns drive letters then it is so simple to avoid this, and you'll never have the problem again."

    In my limited experience, I have never encountered any problem with deleting the entire MountedDevices registry key, or selected entries thereof. Windows always restored the key upon the first reboot. Of course, it is always wise to avoid undertaking any unnecessary or onorthodox action between deleting the key and the first reboot.

    However, I've found that it is also possible to more precisely control the contents of MountedDevices, by creating a few targeted registry files. I've described my particular application in this thread. If you would like to clean up MountedDevices in a controlled way and/or on a regular basis, you might find some inspiration there.

    JustAnotherNoob
     
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