Dual Win 8.1 UEFI boot problem RRS feed

  • Question

  • I tried posting this on another MS community forum, but was redirected to this one.  I feel a bit apprehensive about posting here under the Windows 8 IT Pro heading because I'm very much not an IT pro...   Anyway:

    I have a UEFI PC, the main disk of which was a 2TB GPT formatted HD with the usual 300MB recovery, 100MB EFI, 128GB Win 8.1 boot, and the remaining space as a data partition.

    The original Win 8.1 boot partition has loads of specialised and greedy applications installed that I only use when working for a particular client, so when I'm not doing stuff for him, I wanted to be able to choose to boot to a clean installation with just the stuff I require for ordinary day-to-day work.  I also wanted to take advantage of SSD speed when I need to use the cluttered Windows.

    So I got a 250GB SSD, bought and installed a fresh Win 8.1, allocating 82GB for the installation.  The installer created the usual 300MB recovery, 100MB EFI, and an 80GB boot partition, on which I installed the relatively few items I need for day-to-day work.

    Then with Macrium Reflect, I cloned the cluttered boot partition from the old drive on to 128GB of the remaining space on my SSD (as drive F: ), and used EasyBCD to add the cloned partition to the BCD list.  I was hoping that if I could successfully boot to that installation, it would see itself as drive C:, and automatically allocate another letter to the new lean installation

    However, when I try to boot to this, the UEFI BIOS restarts, but I end up with a blank screen.  In case this had something to do with disk signature collision, I disconnected the HD, but that didn't help.  So I deleted the cloned partition, re-connected the HD and tried EasyBCD again, replacing the previous addition with one for the original boot partition on the HDD, but got the same result. 

    I'm sure this is because I don't understand how BCD works. And no doubt UEFI makes thing ten times as difficult. 

    Anyhow, I'd be very grateful for some advice as to how to make multiple boot work.

    Tuesday, August 19, 2014 6:51 PM


All replies

  • Hi,

    Do you mean to install Windows 7 on an UEFI BIOS?
    We may follow the below blog to install Windows 7 on an UEFI computer:

    Installing Windows 7 on UEFI based computer

    Windows 7 does not inherently have the ability to install into a GPT disk from the base installation.  The Windows 7 DVD is designed to install using BIOS mode.
    Also note that Windows 7 x86 does not support UEFI mode.

    Another thing should be noted is we should install the older operating system first, and then install the more recent operating system. If you don't, you can render your system inoperable. This can happen because earlier versions of Windows don't recognize the startup files used in more recent versions of Windows and can overwrite them.

    Here are some more references:

    Windows 8 Boot Security FAQ

    And a similar thread for reference:

    Dual Boot Windows 7 with preinstalled Windows 8 on GPT-formatted hard disk and UEFI BIOS.

    Best regards

    Michael Shao
    TechNet Community Support

    Wednesday, August 20, 2014 11:47 AM
  • Then with Macrium Reflect, I cloned the cluttered boot partition from the old drive on to 128GB of the remaining space on my SSD (as drive F: ), and used EasyBCD to add the cloned partition to the BCD list.  I was hoping that if I could successfully boot to that installation, it would see itself as drive C:, and automatically allocate another letter to the new lean installation

    I can remember reading about a problem with EasyBCD.  Not sure if the symptom there was relevant here though.  In any case, I think I would go down to basics, e.g. bcdedit, and try to avoid any possible problem from that source.

    Also, regarding "letters", I think it depends on where you are starting from.  E.g. Diskpart done during a Command only boot may give you a different set than you would get from either of your OS.

    Finally  W8.1  seems to be very prone to a blank black screen during startup symptom (distinct from a black screen but I have also seen it give a blank  green screen e.g. my Start Screen color) which then gives the clue that what is being presented is inexplicably the second half of an Extended display.  Fortunately, in this case it is sufficient to just press Win-P, CursorUp, Enter (e.g. try to show the Project dialog and then just continue using the keyboard as if you could actually see to change it from Extend to Duplicate), then wait for the screen refresh and see if you have a better environment to work from then.


    Also, in case you have a problem with old drivers, see this workaround by poster Lz in Answers: 



    Robert Aldwinckle

    Wednesday, August 20, 2014 3:49 PM
  • Michael Shao: Thank you for your attention.  I'm not sure why you refer to Windows 7, since my question does not mention Windows 7, and is concerned solely with Windows 8.1.

    Perhaps I could try stating my problem differently. 

    I would like to create a dual 8.1/8.1 boot facility, but my amateur efforts with EasyBCD do not work.

    This is the current state of the relevant 256GB boot drive: 

    The first 3 partitions were created by Win 8.1 install DVD during installation of virgin 8.1 on to a newly GPT formatted SSD.

    Partition 1: 300MB Windows Recovery;  Partition 2: 100MB EFI system; Partition 3: 80MB Windows 8.1 boot partition.

    The next 2 partitions were created subsequently after the above installation was up and running.

    Partition 4: 128GB clone of a previous fully populated Windows 8.1 partition, (restored from image file, using Macrium Reflect)

    Partition 5: Data partition created using Windows Disk Manager.

    I can presently only boot to the new 8.1 partition, but would like to be able to change the BCD so that I can choose to boot to either this partition or the restored-from-image alternative 8.1 partition

    I would be grateful if someone would tell me how do this correctly using either EasyBCD  or BCDEDIT, bearing in mind this concerns a GPT drive and UEFI bios, with SecureBoot enabled.

    • Edited by kaskeap Saturday, August 23, 2014 10:20 AM
    Saturday, August 23, 2014 9:59 AM
  • Robert Aldwinckle: Thanks for your reply.  I  have seen discussion of problems creating dual Win 8 boot facility with early versions of EasyBCD, which may be those you were referring to, but my understanding is that these issues are fixed in the latest version that I am using.

    As a long-time user of dual monitors, I have seen the problem you mention regarding Extended Display, but for reasons I won't bother you with here, I'm sure this is not my current problem.

    I'm afraid I'm still baffled by BCD in an UEFI environment.  Using EasyBCD I can make my notebook PC boot to two alternatives versions of Win 8.1 (plus XP), but that's with the old-type BIOS.

    The combination of UEFI and BCD seems to be my stumbling block.

    If you have time to read my reply to Micheal Shao above, this might help to clarify my current problem.

    • Edited by kaskeap Saturday, August 23, 2014 10:17 AM
    Saturday, August 23, 2014 10:12 AM
  • If you have time to read my reply to Micheal Shao above, this might help to clarify my current problem.

    Since you seem to have stopped reading my response after the first sentence, I doubt it would be worth my time to try saying any more.

    Good luck

    Robert Aldwinckle

    Saturday, August 23, 2014 2:26 PM
  • @ Robert Aldwinckle:

    Thanks for replying so quickly, and I apologise if it seems that I have missed something in your previous reply.  I've read it again, but still can't understand what it was that I might have ignored or misinterpreted.

    Perhaps I shouldn't have mentioned drive letters at all in my original question, because I don't think the mis-allocation of letters is at the root of the problem I'm having, and I have found that Reflect has a remarkable ability to arrange drive letters logically and conveniently on restoring an image to a different drive.  That's why I didn't respond specifically to your second paragraph.

    And the second paragraph of my last reply to you couldn't have been written unless I'd read and considered your third paragraph .

    If you interpreted my last paragraph as carrying a sarcastic undertone, I can assure you this was not my intention -- I appreciated your original reply and I know how carefully you guys that help us guys have to manage your time.  I just thought that my reply to M. Shao might be more succinct and to the point than my original question.

    I try not to offend others or waste their time, although no doubt I do so more than I know.

    Meanwhile, any pointers to Idiot's Guide to BCD (particularly with reference to UEFI) would still be appreciated.

    Saturday, August 23, 2014 5:20 PM
  • Hi,

    Apologize for the misunderstanding. I thought you would like to use your previous operating system.

    Could you please have a share with the screenshot of your current partitions? I am a little confused about the partitions you mentioned here.

    For the BCDedit in Windows, we may follow the below article to add the boot entry and edit the boot menu:

    Adding Boot Entries

    Note  Before setting BCDEdit options you might need to disable or suspend BitLocker and Secure Boot on the computer.

    Besides, for the UEFI partitions, please see:

    Sample: Configure UEFI/GPT-Based Hard Drive Partitions by Using Windows PE and DiskPart

    How to install Windows 7 or 8 from USB using UEFI

    Best regards

    Michael Shao
    TechNet Community Support

    Monday, August 25, 2014 6:24 AM
  • You can try easyUEFI.

    Another thing, how you dual boot Windows 8.1 here?

    How this two OS installed? Your partitions seems a little not clear here. Screen short?


    Monday, August 25, 2014 6:30 AM