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Decided to give Linux Mint a try (Ubuntu's interface annoys me), so I installed it with the intention of dual booting with Windows 7. Installation went fine, but now I can only boot into Linux Mint. Grub lists two Windows 7 menu options, but selecting either of them causes an "unknown file system" error and dumps me into a Grub recovery prompt. There, I have to manually reset the root and prefix options, as they reset hd0,msdos6 when they should be hd0,msdos5.

I ran Boot Repair twice, once to fix grub errors, once to rebuild the MBR, but it didn't fix anything. Here is the log:

fdisk output:

Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048      206847      102400    7  HPFS/NTFS/exFAT
/dev/sda2          206848  1486249145   743021149    7  HPFS/NTFS/exFAT
/dev/sda3      1486249982  1953523711   233636865    5  Extended
/dev/sda5      1486249984  1945141247   229445632   83  Linux
/dev/sda6      1945143296  1953523711     4190208   82  Linux swap / Solaris


### BEGIN /etc/grub.d/30_os-prober ###
menuentry "Windows 7 (loader) (on /dev/sda1)" --class windows --class os {
   insmod part_msdos
   insmod ntfs
   set root='(hd0,msdos1)'
   search --no-floppy --fs-uuid --set=root 86184D18184D091F
   chainloader +1
menuentry "Windows 7 (loader) (on /dev/sda2)" --class windows --class os {
   insmod part_msdos
   insmod ntfs
   set root='(hd0,msdos2)'
   search --no-floppy --fs-uuid --set=root 56D84F84D84F60FB
   chainloader +1
### END /etc/grub.d/30_os-prober ###

I have found a few similar troubleshooting guides so far, but so far no amount of updating/configuring Grub has been successful. Last resort is, I suppose, use the W7 recovery disc and start over.

Thanks in advance!

Linux Mint 13 Maya, 64-bit

Windows 7 Home Edition, 64-bit

share|improve this question
I chainload win7 on a truecrypt partition, so my setting don't really apply, but I have insmod chain here, maybe you need that, too. – Baarn Sep 8 '12 at 22:19

For mine, I have a couple more lines to load windows 7 than you list. The search with a hint and the parttool may be the missing pieces.

menuentry 'Windows 7 (loader) (on /dev/sda3)' --class windows --class os $menuentry_id_option 'osprober-chain-0CF4A859F4A84734' {
    insmod part_msdos
    insmod ntfs
    set root='hd0,msdos3'
    if [ x$feature_platform_search_hint = xy ]; then
      search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos3 --hint-efi=hd0,msdos3 --hint-baremetal=ahci0,msdos3 --hint='hd0,msdos3'  0CF4A859F4A84734
      search --no-floppy --fs-uuid --set=root 0CF4A859F4A84734
    parttool ${root} hidden-
    chainloader +1
share|improve this answer

Perhaps this guide for dual booting Windows and Ubuntu will help. This lifehacker guide might be of better assistance to a novice user.

share|improve this answer
I've previously dual booted other operating systems before, all without any issue. I'm at the point now where I think grub has taken over the MBR, but Boot Recover or even reinstalling Windows from the disc doesn't seem to work. – JohnB Jun 8 '12 at 16:29

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