How to convert GPT/UEFI to MBR Windows bootable?

Discussion in 'backup, imaging & disk mgmt' started by Solarlynx, Jan 8, 2013.

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  1. Solarlynx

    Solarlynx Registered Member

    Recently I tried to do that in this thread: Win-7 x64: failed to install CTM, RBRX and Keriver !? and failed. The problem is:
    I have bought brand new Lenovo G580 with GPT disk, its booting is UEFI. I want to install a time machine (Comodo's CTM or Rollback RX/Eaz-FIX) but they can't support UEFI/GPT. Windows 7 Ultimate 64 bit is on the computer.

    I want to convert UEFI/GPT to MBR without loss of data and windows reinstall. Is it possible?

    I tried:
    1. Converting a gpt to mbr in Windows Interface or Command line - DISKPART - it said "Disk is not convertible".
    2. I succeeded in gpt to mbr conversion with BIBM and Paragon Disk Manager Pro but couldn't make the Windows bootable.
    3. After conversion to MBR windows rescue disk just said that there is wrong windows and refused to work.

    So is it possible to convert GPT/UEFI disk to MBR without loss of data and windows reinstall?

    Or maybe there are some other time machines (like CTM or Rollback/Eaz-Fix) which support GPT with UIFI boot?

    Thank you.
  2. Robin A.

    Robin A. Registered Member

    It´s not possible, AFAIK.
  3. Jim1cor13

    Jim1cor13 Registered Member

  4. Solarlynx

    Solarlynx Registered Member

    Hi Jim!
    Thanx for your answer.
    The problem is that I can convert GPT to MBR but cannot make MBR bootable.

    I tried it but without Fedora16. I just used Paragon Hard Disk Manager to convert GPT to MBR. As for the rest steps 11-16 they didn't work.

    As for
    I think the aforementioned Paragon make it. Though its command is "Convert basic GPT to basic MBR". I think it's the same.

    I'm afraid Robin A. is correct.
  5. Jim1cor13

    Jim1cor13 Registered Member

    Hi Solarlynx :)

    I think I understand better now what you are attempting, and it would appear it is possible of course to convert, but not without having to re-install the OS after the conversion. Sorry, I sometimes get lost in all of this LOL.

    Maybe this will change, but it does appear only conversion is possible, but after this conversion, it still takes re-installing the OS. The new uefi/gpt type of structure I am not that familiar with, but I am learning something new every day, and i still sometimes lack the understanding LOL Indeed, Robin appears correct, and has a better understanding of this than I do, although I do hope the links were of some help, but preserving data seems not possible at this time. Hard to keep up with so much constant change going on.

    Have a good day Solar :)

  6. MudCrab

    MudCrab Imaging Specialist

    I've been curious about this too. I've done it partially before in testing other things, but never went as far as to get it booting. I think I'll give it a shot and see how it goes.
  7. Solarlynx

    Solarlynx Registered Member

    Thank you guys! I hope sometimes impossible happens!

  8. MudCrab

    MudCrab Imaging Specialist

    I don't currently have a Windows 7 system setup with GPT/UEFI so I tested it on my Windows 8 system. The conversion went fine.

    This is what I did:
    1. Restored GPT/UEFI image to drive using IFW. The drive contained four partitions of a standard Windows 8 install (EFI system partition, Recovery, Microsoft reserved partition, Windows :cool:.
    2. Booted to BIBM and converted the drive to MBR. Before doing the conversion I deleted the Microsoft reserved partition and changed the EFI system partition and Recovery partition to the Normal data type.
    3. Set the Windows 8 partition Active.
    4. Booted to TBWinRE and did a boot repair (this can also be done from a regular Windows 8 repair disc or install disc/media).
    5. Windows 8 booted right up. Booting into WinRE also worked.
    Depending on the system you may also need to adjust some BIOS settings (turn off Secure Boot, for example).
  9. Solarlynx

    Solarlynx Registered Member

    Thank you for instructions. Your Windows 8 has 3 additional partitions. My Windows 7 installation have only 2 additional partitions. It maybe an obstacle.

    Am I right that Paragons' conversion "Basic GPT to basic MBR" must be the same as yours conversion in step 2?

    If yes then the only difference is that I didn't try TBWinRE after the conversion. I'll see if I can try it free.
  10. ratchet

    ratchet Registered Member

    I built a PC last May. ASUS P8Z77-M PRO MB, Ivy Bridge 3570K CPU and x64 W7. I definitely set the BIOS to UEFI. Does this mean I don't have MBR? I can't really tell from computer management. Thank you!
  11. MudCrab

    MudCrab Imaging Specialist

    I don't think it should be a problem.

    Probably. I haven't used it, though. Basically, you just need to convert the drive to MBR without losing the partitions (except for the Microsoft reserved partition).

    You should be able to try it. You should be able to do the repair from a standard Repair Disc also.


    I posted this, but it ended up in a different thread: When I did the repair there weren't any booting files (\bootmgr or \boot) on the Windows partition (which was set Active). I don't know if the existing EFI files could be repaired since I didn't try that -- they are quite different. In my case, the existing files were on the EFI system partition.
  12. MudCrab

    MudCrab Imaging Specialist

    An easy way to tell if you're using GPT is to right click on the drive in Disk Management and see if it shows Convert to MBR Disk in the menu.
  13. Solarlynx

    Solarlynx Registered Member

    Thank you MudCrab!

    Unfortunately Windows Recovery Disk always refuses to work after conversion from GPT to MBR. o_O
    Last edited: Jan 12, 2013
  14. Solarlynx

    Solarlynx Registered Member

    Or just in elevated Command Prompt print "diskpart" then enter. Then "list disk" if your disk is GPT then it will mark it like in the picture.

    Here in the picture Disk 0 is the internal HD which is GPT, the other 2 are connected external disks, which are not GPT.

    Or if you have Paragon or Macrium (free or paid) they show this info.

    Attached Files:

    Last edited: Jan 12, 2013
  15. Solarlynx

    Solarlynx Registered Member

    No, I can't create TBWinRE without a valid license.

    You mentioned "standard Repair Disc", they don't help. I tried all repair options of Paragon HD Manager Pro and all other simpler repair options in disks with Redo, Paragon free, Macrium free, Lazersoft. Windows recovery just refuses to work after conversion from GPT to MBR.

    Maybe I've missed something? Or it's impossible for win 7?
  16. MudCrab

    MudCrab Imaging Specialist

    Just to be clear, you were trying doing the boot repair using the Windows Repair Disc (created using the Start >> Maintenance >> Create System Repair Disc)?

    I know Windows 7's repair can create the files so I don't see why it wouldn't. What I don't know is if it would convert the GPT files to MBR (I haven't tested that). That's why I suggested deleting them so it won't get confused with them. Also make sure Secure Boot is disabled in the BIOS.

    Otherwise, exactly what happens when you try to boot the Repair Disc? Does it error when booting (what's the message?) or does it only error after you try to run a startup repair?

    I'll check if I have a Windows 7 GPT/UEFI system backup saved. If I do I can run a test on that, otherwise I would have to setup a system to test.
  17. zmechys

    zmechys Registered Member

    Within 10 days of upgrading Windows 7 to Windows 8, I've needed to refresh Win 8 two times. After 10 days "happiness" with Windows 8, my computer crashed for good. Nothing worked. Could not refresh, could not reset my Windows 8. I could not even run chkdsk with MS-DOS.
    I tried to repair Windows 8 with USB Flash Drive, but got a message saying, that my hard drive is locked.
    When I mentally agreed to wipe out all my data, files, etc., and do the clean install, I got another message "cannot install on GPT disk."
    Only after reformating, I was able to install Windows 8.
    Where can I get more info about that MBR/GPT issue for Windows?
  18. Solarlynx

    Solarlynx Registered Member

    Yes, exactly this disk. What is interesting I have 2 Lenovo notebooks G570 and G580 with Win 7 home 32 bit and Win 7 Ultimate 64 bit (here I have this GPT) and these Windows Repair Discs work only on the comps where they were created.

    No it cannot. Even more after conversion of GPT to MBR (with other tool, now I use Paragon HD Manager Pro, and earlier I used BIBM trial) this Windows Repair Disk refuses to boot: it says something like "~the wrong version of Windows".

    After conversion from GPT to MBR (with other tool) this Windows Repair Disk errors when booting, says as I wrote something like "wrong version of Windows". If you need all details I can repeat conversion and boot this Windows Repair Disk to see all the details.

    BTW windows installation disk (win 7 Ultimate 64 bit) has its own repair. When I use it, it goes till the startup repair and says that there is no errors.

    I never tried it. I'll see.

    Thank you very much, MudCrab.
    Last edited: Jan 12, 2013
  19. ratchet

    ratchet Registered Member

    MudCrab and Solarlynx, thanks for the how to(s) and indeed I'm MBR not GPT! The reason I asked is because I've always been able to wake the XP desktop over the internet by sending a magic packet and a script in my Tomato firmware. Despite every setting known to man, I can only wake this W7 PC over the LAN. From researching the problem it would appear that it is definitely a hit and miss proposition with W7, i.e. many ex XP folks can't get it to work, yet some can. So I was "reaching" for any possible cause! I just thought of another angle, which would make no sense, but besides the operating system the one major difference is a SSD. I might start exploring that possibility. Thanks again!
  20. Solarlynx

    Solarlynx Registered Member

    :D :D :D :D :D :D :D :D :D

    I finally managed to convert GPT to MBR. It was very simple.
    1. I disabled EFI boot in BIOS.
    2. Converted GPT to MBR with Paragon HD Manager Prof. IMHO this step can be done with BIBM or maybe Diskpart command or from within Windows Disk Management if somehow to boot with disabled EFI.

    That's all.

    Thank you MudCrub, Panagiotis and all who gave me hints in these both threads.

    :) :) :) :) :) :) :) :) :)
    Last edited: Jan 13, 2013
  21. Jim1cor13

    Jim1cor13 Registered Member

    Very good to hear Solarlynx :) Had you tried what you stated previously, or had you not disabled EFI boot? What did you do that finally made it simple? Was the trick to first disable EFI boot, or just finding the right conversion tool? I agree, BIBM should certainly handle this, but maybe Paragon just made it easier?

    Thanks for sticking with it, it should be very helpful for others who are looking to do the same :)

    Have a good day!

  22. Solarlynx

    Solarlynx Registered Member

    Thank you!
    The only new trick was first to disable EFI boot in the BIOS. Then just GPT to MBR conversion. And voila! The windows booted without any other operations.

    Only these two steps. Windows in disk C and all data in disk D stay intact.

    I hope it will be helpful to those who try to do it.

    P.S. I had to burn new Windows Rescue Disc as the disc which was burnt from Windows in GPT refused to boot.
    Last edited: Jan 14, 2013
  23. Jim1cor13

    Jim1cor13 Registered Member

    Good job Solarlynx :) You kept with it until you figured it out, and I am sure it will be good reference for others :)

    I would imagine the rescue cd would not work due to EFI being disabled? Good to hear the new disc works. Well done.

  24. Solarlynx

    Solarlynx Registered Member

    Thanks again Jim!

    I go on enjoying all pleasures of using a snapshot time machine (here I first installed Comodo's CTM 2.8 and it works impeccable so far, so most probably I'll stay with it - I don't like Rollback's issues with licenses, though it works a bit quicker).

    All this fuss around conversion was only due to inability of all known to me time machines to work with GPT. I don't see any other trouble with GPT/UEFI.

    No the first Windows Rescue Disc (which was created when Windows was on GPT/UEFI disk) didn't work due to conversion from GPT to MBR. This is a bug in Windows. In case if the partitions before the System Partition (usually "C") are damaged then this Windows "Rescue" Disc may be helpless to fix them. Fortunately there exist a bunch of good free/trial/paid products which handle it easily.
  25. zapjb

    zapjb Registered Member

    This is good info. Thanks. I have a new Lenovo laptop awaiting unboxing. If it's the new fangled I'm going to be changing to MBR quickly.
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