[SOLVED] Need help undoing Windows 7 changes to Windows XP boot partition

Discussion in 'Windows XP / Older OS' started by OldCompguy, Sep 29, 2011.

  1. OldCompguy

    OldCompguy MDL Novice

    Sep 29, 2011
    #1 OldCompguy, Sep 29, 2011
    Last edited: Sep 30, 2011
    Hello All,

    I tried installing a copy of Windows 7 Ultimate on a bare hard drive in my system.

    I did not disconnect the other drives. I got the Windows 7 running and updated,
    but my Windows XP installation is not working. This is what I get:
    chainloader /bootmgr

    Error 13: Invalid or unsupported executable format

    Press any key to continue...

    I press any key and get brought to the red GRUB4DOS screen


    I can still boot XP using Hirens 10.4, and selecting the XP ntldr option.

    So apparently, I have not gorked the patient. However, I cannot boot
    normally, that is without Hirens.

    Can someone tell me what I need to remove, or undo, to restore my normal boot?

    It seems that something is cutting in before ntldr, but Hirens can bypass it.

  2. IronMaiden

    IronMaiden MDL Member

    Oct 27, 2009
    bootmgr belongs to Windows Vista/7 and isn't the correct file to load Windows XP with...best to take a look at your BCD store with EasyBCD (from within Windows 7). It also lets you create a new entry to boot your XP partition correctly.
  3. OldCompguy

    OldCompguy MDL Novice

    Sep 29, 2011
    #3 OldCompguy, Sep 30, 2011
    Last edited: Sep 30, 2011

    Tnanks for the reply IronMaiden,

    I am not familiar with Windows 7 and this is the first time I have installed it on a machine.
    I was careless to install it on the clean drive while the rest of my drives were connected.
    I am not a fan of dual boot systems with different operating systems controlled by a boot
    manager. I installed Windows 7 on a clean drive in a removable drive bay. My goal was to
    select the boot drive in the BIOS boot options if I wanted to override my default boot drive.
    Will EasyBCD reconfigure the XP boot drive so that it can boot without the Windows 7 drive
    connected? I would like to keep the two OS's completely separate as I gradually switch to
    Windows 7. The full switch won't happen until I can build a new machine. Right now I'm using
    a machine using an MSI 7514 motherboard and and Intel duocore E7200 CPU.

    I was in a hurry and did not open the case to disconnect the other drives. Apparently, the
    Windows 7 installation process "saw" the XP drive and did something to the MBR. Now the
    XP drive looks for the bootmgr to decide what should boot. I have had no luck with various
    utilities or the recovery console to rebuild the MBR (fixboot, fixmbr). Either the utilities would
    not work, or in the case of the recovery console, I cannot access it. Through all of this I can
    still boot the drive with Hiren's 10.4 using the advanced boot options. As near as I can figure,
    that option ignores the MBR and goes straight to ntldr. I need to fix the MBR so it points to
    ntldr again. I hope I am making sense here.

    Any help is appreciated.

  4. 911medic

    911medic MDL Guru

    Aug 13, 2008
    with the xp install disc, boot to the recovery console. Then use the following at the prompt to the windows xp install. If the windows XP install is at C: then..




    this will allow you to boot to the xp partition..
    Stop hovering to collapse... Click to collapse... Hover to expand... Click to expand...
  5. OldCompguy

    OldCompguy MDL Novice

    Sep 29, 2011
    Problem Solved

    I did not want to run Windows 7 alongside my Windows XP drive. I did not try it, but while I was solving
    the problem (see below) on the crippled machine, I found this comment in the forum browsing around with
    another machine on the home network:

    To IronMaiden:


    "steve February 14, 2011 at 4:24 pm

    I'm sorry if this has already been mentioned, but the program "EasyBCD" can be installed in XP,
    and will provide you the ability to modify the Vista/Windows 7 bootloader, or even revert to the
    XP MBR with one click. No need for any DVD or command prompts."

    I did not try to run it from within XP. Anybody out there know if this will work?

    To 911medic:

    I could not access the recovery console on the hard drive, and trying to use the XP install disk
    resulted in bluescreens.


    I had two partitions on the boot drive. I installed a parallel copy of XP on the second partition.
    this restored the MBR to "XP condition" and got rid of Windows 7 changes and bootmgr interference.

    [I had tried a number of MBR repair utilities with no success (MBRfix, Partition Table Doctor 3.5, MBRwizard, et. al.)]

    The boot.ini file on the C: drive (original XP installation) then had the parallel XP installation as the default.
    The boot menu still had my old options, and I just needed a quick finger on the scroll down key to select my
    old XP installation. Then I edited the boot.ini file to make the old installation the default again.

    Everything works just fine now. I'll clone the drive to another, and start messing with Windows 7 again......

  6. DesertJerry

    DesertJerry MDL Novice

    Apr 11, 2010
    I have EasyBCD installed on XP Pro, XP Pro x64, and Win7 Ultimate 64-bit w/SP1 and I highly recommend it for its ability to assist in setting up and/or selecting dual/multi-boot systems.