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I first installed Windows 7 Ultimate and then Ubuntu 10.04 on my laptop. Now I can boot to Ubuntu, but cannot boot to the Windows 7, even the boot loader has menu for Windows 7. I select Windows 7 in the menu and press enter for booting, but the computer just restart and return to the boot loader menu for selecting a OS, including Windows 7. Would somebody give me some clue to help me get to the Win7 system?

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migrated from Aug 7 '11 at 3:27

This question came from our site for professional and enthusiast programmers.

Might be better on superuser. Migrate? – L84 Aug 7 '11 at 3:16

I bet your GRUB does not refer to the true winload.exe and bootldr.mbr for your Windows. If you use /fixmbr and /fixboot, windows overrides the bootloader files and your Ubuntu installation will lost.

You should, therefore, edit GRUB manually in Ubuntu correct the fields related to Windows, here is my bootloader file to give you a clue. GRUB should read these fields differently but the idea is more or less the same.(I stripped the unique keys)

Windows Boot Manager
device                  partition=\Device\HarddiskVolume2
description             Windows Boot Manager
locale                  en-US
timeout                 10

Windows Boot Loader
device                  partition=C:
path                    \Windows\system32\winload.exe
description             Windows 7
locale                  en-US
recoveryenabled         Yes
osdevice                partition=C:
systemroot              \Windows
nx                      OptIn
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This article addresses your issue:

[How To] Fix MBR after installing/uninstalling Windows/Linux in a dual boot

From the article:

For Windows Vista: Boot from the installation CD/DVD and enter “Repair Windows” link at the left hand bottom of the dialog. Then go to command prompt . There run “bootrec /fixmbr” and “bootrec /fixboot” commands one after the other. That does it.

It is important to note the term "MBR" or master boot record. If this article doesn't help you, some searches on how to fix Windows 7 master boot record should get you back on track.

Sorry I couldn't provide specific details!

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Have a look here.

Also take a look at wubi for your next ubuntu install, it's like magic xD.

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It sounds like the exact converse of what fastreload writes has happened. You installed Ubuntu over Windows 7, and GRUB2 has scribbled all over your bootstrap programs. You need to decide what order you want your bootstrap to operate in, and then fix/reinstall your boot manager accordingly.

In all cases, you need to ensure that …

  • … you have a separate system volume (which you will have if you installed Windows 7 on a blank hard disc);
  • … Microsoft's Boot Manager and the BCD store are installed in that system volume (As Microsoft explains, bcdboot and bcdedit with the /import option can be used to copy over the Boot Manager and BCD store from another location if they are somewhere else.);
  • … the system volume's bootstrap, in its Volume Boot Record, starts up Microsoft Boot Manager (bootsect /nt60 SYS fixes this, once the system volume is properly set up and recognized by Windows 7.);
  • … the BCD database has an entry listing your Windows 7 boot volume;
  • … GRUB2 (wherever it is) is told where the Linux kernel is.

You might want Microsoft Boot Manager to be your primary bootstrap program, with one of its entries chaining to GRUB2, in which case you need to ensure that …

  • … the Master Boot Record bootstrap chains to your system volume (This is standard behaviour. If your system isn't currently doing this, because GRUB2 has scribbled over your MBR, then bootsect /nt60 /mbr sys will fix it, as would the fixmbr tool from older versions of Windows NT.);
  • … the BCD database has an entry listing your Linux boot volume;
  • … GRUB2 is installed in the Linux boot volume.

You might want GRUB2 to be your primary bootstrap program, with one of its entries chaining to the Microsoft Boot Manager, in which case you further need to ensure that …

  • … GRUB2 is installed in a separate active partition, somewhere else other than the system volume;
  • … GRUB2 is also told where the system volume is.

As noted in other answers, you can access tools like bcdedit and bootsect from the Windows Recovery Environment that is available from your installation disc.

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