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  1. #1
    Ken Kashmarek

    Question Dual booting an image of a Win7 partition - problems encountered

    I have a system with XP (vendor OEM installed) & Win7 on disk 0 & disk 1 (respectively). Win7 boot manager works fine with this (also worked fine with Win8 installed on disk 2 but Win8 has been removed from disk 2 and from the boot selection list).

    I wanted to upgrage the 80 gig drive on disk 1 to a 250 gig drive (drive 0 is 250 gig already). I cloned (Acronis True Image 2011) the 80 gig drive to the 250 gig drive (installed on drive 2). This was the easy part.

    I unplugged the 80 gig drive but the subsequent boot selection for Win7 failed (could not find a targetable boot drive probably due to recent hardware/software change; duh).

    I swapped the SATA connector and the boot still failed (only the 250 gig online).

    I plugged both drives to their former SATA connectors and the boot selection worked. I swapped the SATA connectors for drive 1 and drive 2 and the boot still succeed, again finding the 80 gig drive.

    I have to ask Acronis why the cloned image didn't work. However, the problems didn't stop there.

    I attempted to add the 250 gig drive to the Win7 boot manager menu by using Visual BCD Editor (using F9 which scans for bootable systems and adds them to the boot manager database). That worked, and I could select the clone and boot to it.


    When switching between XP and Win7 (drive 0 and drive 1), the boot manager would change the Win7 selected drive to C: and the XP drive to N: (and back when XP is selected).

    When selecting the Win7 cloned drive, the boot manager DID NOT change the drive designation to C: (as it had with my former Win8 RP install). Instead, the original Win7 stayed as C: and the clone became E:, which caused the E: boot selection to crash, lock up, or fail (with damage yet unknown).

    Is there a way to dual boot Win7 (partition to partion or disk to disk) WITHOUT doing a full install of the 2nd Win7 system? What must be done to get this Win7 clone to work within the existing Win7 boot manager environment?

    Your feedback is greatly appreciated if you have resolved this situation or have experience with such a configuration.

    Now, you may ask, why try to multi-boot to the clone? Well, I wanted to upgrade the disk drive, and then boot from the upgraded drive. This did not work as expected as the boot manager was looking for the original disk and would not use the clone. How does one upgrade a Win7 drive and make it work?

    Thank you.

  2. #2
    Ken Kashmarek
    I should add that the cloned Win7 disk did not involve any hidden vendor partitions. The clone operation was run from the Winxp system on the computer. Other reading indicates the perhaps I should have used a standalone cloning program booted from a CD or recovery disk.

  3. #3
    New Lounger
    Join Date
    May 2011
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    You cannot simply clone a Windows 7 partition and expect that the copy will work.
    The reason is that that there are links in registry which point to original partition.

    Disk signature and partition offset makes up an "absolute" address and this is mapped to a drive letter.
    See in registry:
    HKLM\System\MountedDevices\DosDevices\A ( Z)

    How to fix partition address to drive letter mapping:
    The main principle is to swap drive letters so that C: is mapped to Windows OS partition. You can involve some unmapped temporary drive letter for swapping.
    After swapping you reboot and the mapping scheme should correspond to "normal" mappings.
    You can always use DiskManagement to map and unmap drives (except OS drive and boot(system) drive !)

    I am not sure but running StartUp Repair several times with rebooting after each run maybe can fix mappings too - have not used it as manual fixing is my preferred way.

  4. #4
    Ken Kashmarek
    According to some vendors, you can use their "clone disk" function, shutdown, swap the drives, and reboot. By and large, that works if the disk is cloned by booting the cloning software from a CD/DVD and the cloned drive is drive 0, which is typically the boot disk. You really don't want to create a clone of a disk that is currently booted and running the program that is performing the clone operation (though possible to complete and work, you don't have a true clone of the source drive).

    In my original post, I pointed out that I cloned an entire disk, which contained the OS partition that is involved in a dual-boot environment. You can clone a singe partition but that is considered taking an image of the partition. Typically such an image is generally not for a bootable OS but can be.

    In my dual boot environment, when disk 0 is booted (WinXP), it is C: and Win7 on drive 1 is N:. When Win7 is selected, the Win7 boot manager makes that partition on drive 1 to be C: and the XP partition on drive 0 becomes N: (my choice of driver letter assignment via Disk Management when running Win7).

    When I swapped the cloned disk with the original drive, selection of Win7 from the boot manager list produced an error that the bootable image could not be found, but produced a message to use the install disk and run startup repair. It scanned the disks, found an error in the boot manager database, applied a correction, and subsequent reboot returned the system to normal operation (required only one pass). This indicates that cloned disk is different than the original disk and carries some unique signature which is placed in the boot manager database. I have a listing of the database before and after the correction, so this can be identified (but probably not ahead of time). This also implies that I could add the old copy of the cloned disk to the boot manager selection list (using Visual BCD Editor) and use it as well. Visual BCD Editor also provides a Startup Repair program which would also correct the issue.

    I suspect that if I have to change drive 0 (the original WinXP vendor supplied disk that came with the computer), I will have to perform similar steps.

    This was done using MBR disks (master boot record). I haven't tried it with the new disk layout that vendors are using on 1 TB drives (this new layout is required for 2 TB drives and larger).

  5. #5
    New Lounger
    Join Date
    May 2011
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    When you clone (= exact copy) you have the same disk signature.
    If cloning software cares about creating a new disk signature it has to replace all references to old disk signature with new signature.

    Where do we have references:
    1. registry
    2. BCD (is not part of system registry hives, but is mirrored after boot/OS load to HKLM\BCD0000000)
    3. Restore points.
    Any other system files containing "absolute" references ?? I don't know.

    I don't think you can easily create a 100% working cloning solution and can never be 100% sure that clone will not show problems later.

    I think GPT disks have a GUID signature (MBR disks have a 32bit signature). GPT partitions have also their own GUIDs.
    And a GPT disk can have also a "real" MBR (usually GPT disks have a "protective" MBR) so this is another level of complexity.

  6. #6
    Ken Kashmarek
    I believe that cloning software does not change any disk contents, just copies the disk contents from one device to another (get it, CLONE). Registry is not changed and restore points should not be affected since the purpose of a cloned disk is to take the place of the former drive, and as such, should look identical.

    The issue I had dealt with the disk being recognized by its entry in the BCD, and at boot time, when a selected entry could not be found, the attempt failed. I believe the cloning software has no recognition of the BCD and/or the boot (dual boot or multi-boot) environment.

    Once the repair startup function ran, it recognized the mismatch between an existing bootable drive OS entry in the BCD and what was on the actual bootable disk. Then entry was changed by the repair starup function, and the subsequent boot succeeded.

    I have used the Visual BCD Editor to add the old Win7 selection back into the BCD but have not test booted it yet.

  7. #7
    Ken Kashmarek
    I have achieved results.

    I used Visual BCD Editor to once again add my old Win7 (former small disk drive) to the BCD. It did but the entry appeared incomplete.

    So, I booted my Win7 install CD and went to startup repair, where it found something to be changed (corrected or adjusted). With that done, I then rebooted and selected the old Win7 entry, it booted as C:, switched the former Win7 to O: and it all works. Thus, one can produce a clone of a running system, bring it up in place of the old system, then bring back the old system and use it as well. It takes a couple of Win7 install disk startup repair runs to keep it all together.

    Thanks for feedback provided by others.

    (now, maybe bring back that Win8 RP system...)
    Last edited by Ken Kashmarek; 2012-12-09 at 11:55.

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