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My main machine is a desktop with Win7 (6 months old) & I installed an older version of ubuntu onto an external drive. Once ubuntu was installed I updated ubuntu ...
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  1. #1
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    Can no longer boot Win7, grub error


    My main machine is a desktop with Win7 (6 months old) & I installed an older version of ubuntu onto an external drive. Once ubuntu was installed I updated ubuntu to the latest version (10.04) from within ubuntu. Ubuntu works fine but when I disconnect the external drive with ubuntu on it in order to load windows, I get 'No such device: 3538c7a0-2fbe-4518-8248-d22d2be0558b Grub Rescue>'

    I don't care about having ubuntu at this point & would simply like Win7 back without reinstalling completely (if possible). My win7 cd doesn't give the option to 'repair' after selecting language.

    Any help is appreciated.

  2. #2
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    That problem is usually the result of installing part of the Grub files to the master boot record on the internal drive. When you disconnect the external drive with Ubuntu, Grub can no longer find the files it needs which are on the Ubuntu partition on the external drive.

    I doubt you have a windows 7 installation disk but, if you do, you should be able to repair it with that. If you do not have an installation CD for windows, you can use a Recovery CD to access the Recovery partition for windows 7, assuming it was an OEM install and it has a Recovery partition?

    If you don't have an installation or recovery CD, go to this site where you can download a recovery CD. Make sure you download the one for windows 7 not vista. I would suggest reading the entire page of instructions before doing anything.

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    Thanks for the reply,

    I just realized that if I keep my external drive connected & powered while starting my desktop, I can get windows to load, allowing me to access my desktop & files etc. When I power up with the external drive connected, unbutu loads first & the first screen is titled 'GNU Grub Version 1.98-1unbutu7,' here I have a few options & the last is 'WIndows7 (loader) (un/dev/mapper/isw-dhdcidejge_ARRAYO2' which allows windows to load. So at least I can access my files to backup in case a reinstall is needed.

    The cd that came with my machine is titled 'Microsoft Windows 7 Home Premium 64 bit' which allows me to reinstall. Tech support told me that this cd usually gives the option of repairing, but since the option is not there it's only good for a reinstall at this point. I did notice a recovery partition when booting from this cd when it asks where to install windows, so I guess a recovery cd is my next option.

    Which site are you referring to when you suggest downloading a Win7 recovery cd? Once I have a recovery cd do I simply boot from the cd & follow the instructions?

    Thanks

  4. #4
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    I just realized that if I keep my external drive connected & powered while starting my desktop, I can get windows to load
    That's correct. As I indicated in my previous post, there are a number of files used to boot Grub and the stage1 file is in the master boot record. It basically points to the partition on which your other Grub files (including the menu.lst or grub.cfg) exist. That's where the menu you see is.

    The default installation will install the Grub stage1 to the master boot record of the first drive which appears to be what happened in your case.

    Sorry I forgot to post the link last time, read the page before you begin anything so you have some understanding of it and make sure you download the windows 7 version.

    Recovering the Vista Bootloader from the DVD - NeoSmart Technologies Wiki

    You should be able to click on the Repair Your Computer item in the lower left of the screen once you boot from the CD.

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    Ok, I succefully created a recovery disk & booted from this disk. I clicked on 'startup repair' to automatically fix the the problem but it states no problems found. I then went to step three which explains manually repairing the bootloader. I entered the first string of commands & the cpu tells me which commands are supported (FixMbr, FixBoot, ScanOs & RebuildBcd). The second string of commands is "C:\boot\bcd bootrec.exe /rebuildbcd" but I get an error stating "Invalid Switch - rebuildbcd."

    Am I doing something incorrectly or is this part of my issue?

    Also, if I use my external drive to load win7, could I then use the EasyBcd program to 'reset bcd data?'
    Last edited by burns718; 10-21-2010 at 11:53 PM.

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    Not sure which step actually solved my issue, but my computer now boots win7 normally again, no cd in the drive & no external drive connected. I restarted after my last post & it booted normally

    I'll be backing up for sure since I haven't done so with this machine. Would it be worth while installing the easybcd program do you think?

  7. #7
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    Would it be worth while installing the easybcd program do you think?
    You can download the CD from the link I gave you in the last post, burn it to a CD and boot from it to repair. You can also go to the neosmart site and download EasyBCD which will download to your Desktop and you can modify your windows bootloader with it. With the second option, it's not much good if you can't boot into windows.

    I have EasyBCD on the Desktop as well as the CD. You could do both. I rarely boot into windows so it doesn't really matter in my case.

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    I'll do both just to have them for future reference. I haven't messed with bootloaders much & doubt if I'll start anytime soon, having only one machine.

    I really appreciate your responses, I thought it would take much longer to find a solution other than reinstalling.

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