Creative solution required...

Discussion in 'backup, imaging & disk mgmt' started by TheRollbackFrog, Aug 27, 2015.

  1. TheRollbackFrog

    TheRollbackFrog Imaging Specialist

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    An UEFI Secure BOOT system (MBR-based disk) has gone belly up. All required partitions (EFI, MSRP, etc) except the Windows partition (original C: ) have been destroyed (cannot be reconstructed).

    Goal... I would like to use the existing Wndows partition (C: from above), if possible, in a LEGACY/MBR configuration rather than UEFI (both are available).

    What's the easiest way to get from where I am to my goal, if even possible? It's easy to ACTIVATE that existing partition but I know the required BOOT files are not on it.

    Any creative suggestions? (I don't have BIBM but can probably get it, if necessary... any other method probably better due to limited knowledge of BIBM).
     
  2. oliverjia

    oliverjia Registered Member

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    LOL it appears you've already read this below thread, where the mud crab used BIBM to make this possible. AFAIK, you'll have to purchase BIBM to do it Mr. Frog. It appears regular set active and Windows repair do not work.

    Code:
    http://www.wilderssecurity.com/threads/how-to-convert-gpt-uefi-to-mbr-windows-bootable.339321/
     
  3. Brian K

    Brian K Imaging Specialist

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    TRF,

    A challenge although I don't understand the problem. Is the system UEFI or MBR? You mentioned both in the first line. What happened to the system? How do you know the Windows partition is OK and the other partitions aren't? Any backup images?
     
  4. MudCrab

    MudCrab Imaging Specialist

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    You could create a backup image of the Windows partition, delete partitions and wipe track 0, restore back to it as MBR. Another option, if you have IFW/IFL/IFD, would be to use the "Change Disk" feature (delete EFI System first if it exists). Once converted, proceed normally.

    Boot to the Windows media (installation or repair, in Legacy mode), open a Command Prompt, set the partition active, make sure bootmgr is in the root folder (usually Win8+ already have it there), delete any existing \Boot folder, then create the booting files: bcdboot c:\Windows /s C:

    If the partition has a different drive letter than C: use what's correct.
     
  5. TheRollbackFrog

    TheRollbackFrog Imaging Specialist

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    Morning Brian and MudCrab! Finally getting a chance to get back to this.

    Brian... you asked if the system was MBR or UEFI... it is both. What's strange about this one is that it's a single MBR-based HDD that's hosting the required EFI and MSRP partitions usually involved in UEFI BOOTing... and it was set for SECURE BOOT. Other than this one, every other UEFI BOOTing system I've seen used GPT disks instead of MBR-based disks, but apparently they're not mutually exclusive... an UEFI BOOTable system can be built using either GPT or MBR-based disks... I didn't know that.

    Anyway, what the system had on it (a 500gB HDD) was a 1gb "WinRE and Tools" partition, an EFI (System) partition, the Windows partition <C:>, another unlabeled 450mB partition (I think this was the one created by the W8 to W8.1 upgrade) and a factory recovery partition from the OEM (HP). My guess is that the 450mB unlabeled partition was the "new" MSRP created (and used) during the W8.1 upgrade and the 1gB earlier partition was cast aside following that upgrade... just a guess here, though.

    Anyway 2... the system arrived on my desk with performance problems (I saw the system once before). This time it was basically as I sent it back the first time but with serious browser performance problems when using Yahoo email (mattered not what browser). I decided, after doing some basic testing that the 5K+ msgs in her InBox had the most to do with the browser's client/server performance issues. Restructured her email system and performance was much better, although still sucked pretty badly. This has a lot to do with the configuration of her desktop... basically a very low powered laptop built inside a desktop case (a pathetic piece of hardware from HP).

    Anyway 3... when finished, I decided to defrag her system using MyDefrag which I've used a thousand times before for basic system cleanup, followed by a fresh system image (she had none before this). A reBOOT after the defrag and prior to the image caused the system to become unBOOTable... I have no idea why. I don't have the various error msgs in front of me but they lead me to believe that the system never made it to the BOOTmgr portion of the process, leading me to believe that something happened in the BOOTing process prior to ever being vectored into BOOTmgr. A rebuild of the MBR using the Minitool Partition Wizard's tool caused no change in the problem.

    At this point I made the assumption that the Windows partition was probably OK (due to the error msgs I had received) and that something had happened between the MBR thru the EFI thru the MSRP to BOOTmgr in the Windows C: partition. Basically that's my question... I'd like to take that hopefully in tact C: partiiton and hook it directly up to the MBR to simplify this currently broken BOOT path rather than try and reconstruct the pieces in the UEFI BOOT path (I personally do not like UEFI configured systems... too many variables and some specs are really not settled yet in some areas). Remember, there is no image of this system at present.

    I have just imaged the broken system, including what I believe to be all the pieces of the broken system (original 1gB WinRE Tools, EFI, Windows, and new 450mB MSRP (I left the RECOVERY partition out of the mix for the time being... it's really not needed and has absolutely no value following this problem). I'm going to try a variation MudCrab's suggestions first (wiping all partitions except Windows but leavig it where it currently lives on the disk <not restoring>... it shouldn't make any difference), and if the variation doesn't work I'll follow the suggestion to the letter. I'll be back with some results later on.

    Thanks to both of you for all your help and suggestions with this. And thanks for the thread, Oliverjia... it was an interesting read.
     
  6. TheRollbackFrog

    TheRollbackFrog Imaging Specialist

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    I'm baaaaaaack!

    MudCrab, you are a genius and my hero!! The system LIVES once again.

    The variation I used on your procedure was I imaged the system but didn't wipe everything and restore the image. I just wiped all the partitions except the existing Windows partition (left it in place <no restore> so I wouldn't overwrite any of the other partitions I just deleted... just in case :) ). Made sure Bootmgr was in place, rebuilt the MBR, set the Windows partition to ACTIVE and ran your "bcdboot" suggestion... all is well and happy (I thought that partition would be OK... just needed to straighten out the BOOTing path and configuration). The current Windows partition is out on the disk a ways (about 1.5gB) but that can easily be moved, if necessary (it doesn't need to be moved right now... she doesn't need the space)... the system is being imaged as I type.

    I learned a coupla things today and both are very useful. I was aware of but never used "bcdboot"... a very useful tool in reverting UEFI-based systems to Legacy-based systems. And the fact that GPT and MBR based disks are both supported under the UEFI environment... I really didn't know that. The only thing that appears to be a requirement of UEFI is the EFI "System" partition... the disk format (GPT vs MBR) seems to be completely independent. The only issue would be that when using an MBR-based disk, you will lose one of your PRIMARY partition capabilities in the form of the EFI "System" partition when using UEFI BOOTing. And this system surely doesn't need SECURE BOOT for this 96-yr old owner (she's amazing).

    Thanks again, everyone (you, too, Pete) for all your help with this... I am thrilled with the result (and am ready to destroy any additional UEFI systems I find out there :ninja: )
     
    Last edited: Aug 28, 2015
  7. Peter2150

    Peter2150 Global Moderator

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    Hi Froggie

    Glad you got it.

    Pete
     
  8. Brian K

    Brian K Imaging Specialist

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    TRF,

    Thanks for that fascinating explanation which is way over my head. I'd be interested to hear MudCrab's thoughts on this issue.
     
  9. TheRollbackFrog

    TheRollbackFrog Imaging Specialist

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    Brian, I have this vague memory of recent Windows REQUIRING a GPT formatted disk when doing an installation on an unformatted HDD... I may be wrong, though. That's what may have me believing that MBR-based disks were not workable with UEFI. I don't believe I've ever tried to build an UEFI-based Windows system on an unformatted HDD (as I've said before, I do not like UEFI systems... yet o_O )

    I just may do this as an exercise...
     
  10. Brian K

    Brian K Imaging Specialist

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    I've played with dozens of UEFI installs now, Windows and Linux, and I feel comfortable but I still prefer MBR systems. There is so much more you can do with a MBR system.

    UEFI installs... start with an empty drive. It will be a MBR drive if it is empty and the Windows install will create the GPT drive. In the Custom install window select New and type a size your your OS partition. Windows will automatically create partitions like this... (Win10)

    Recovery 450 MB
    EFI System 99 MB
    Microsoft Reserved (MSR) 16 MB
    Win10 (your size as above)

    If Windows plays up you just have to restore your OS image. If the drive fails simply restore your Entire Drive image to an empty drive.

    It's not critical how you restore images if you want to be creative. You can restore partition images to an empty drive in random order. The OS will boot.

    If you want to do a MBR install with Win10, it's the same procedure as previous operating systems. UEFI/BIOS in "Other OS" mode (not Secure Boot), CSM enabled in the BIOS and boot the install disk in MBR mode. You can install to a partition or a blank drive. If you don't want a System Reserved partition you have to create the intended OS partition prior to booting the install disk.
     
    Last edited: Aug 28, 2015
  11. TheRollbackFrog

    TheRollbackFrog Imaging Specialist

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    Thanks, Brian... that definitely fills in some gaps. And through this successful exercise, I can now move an existing built system from UEFI to Legacy-MBR without rebuilding... a very useful piece of knowledge.
     
  12. MudCrab

    MudCrab Imaging Specialist

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    I ran some tests with this scenario and it seems that the BIOS just needs to support booting that way. For example, I took a standard UEFI GPT disk (Windows 10), deleted the EFI System partition and MSR, converted to MBR, restored the EFI System partition, changed it to FAT32/Active, updated the BCD and it booted right up into Windows in UEFI mode. However, WinRE was broken and wouldn't boot correctly after repairing (I didn't dig into fixing it).

    Personally, I would avoid setups like that since most software/tools (and Windows) will expect MBR/Legacy and GPT/UEFI configurations. That being said you should be able to quite easily convert from MBR/UEFI to either other standard if you do end up with one.
     
  13. TheRollbackFrog

    TheRollbackFrog Imaging Specialist

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    Thanks, MudCrab! By the way, that configuration came from HP's "factory" as an OEM model ("P2" I Believe... it's not on my desk at the moment). It's probably one of the worst hardware configurations I've ever seen. It comes in a mid-Tower case and has nothing in it but a mini-ITX mainboard with an AMD E-series (dual core at 1.4ghz with a tiny L2 cache) SOLDERED on to the mainboard... unbelievable (and the poor lady paid $485 for that POS)!

    When I first picked it up, I thought it was an empty case!! It uses a laptop AC Adapter for power... no internal power supply.
     
    Last edited: Aug 31, 2015
  14. TheRollbackFrog

    TheRollbackFrog Imaging Specialist

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    Thanks to you, that's what I did with hers... it's now a Legacy-MBR system and runs just fine. Thank you once again!
     
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