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Everybody will understand this problem I think, but somebody will have the solution (I can't find it on here even after searching). It's a straightforward (!) boot up issue (I wish!!!!).

I have a laptop with several partitions. One of them is Ubuntu 12.04.1, another is Oracle VM, another is Windows XP etc. I made an adjustment via a partition manager within XP and upon the re-boot I've got the dreaded "grub rescue>" prompt.... I cannot boot from CD or USB versions of any of these; Windows XP, Ubuntu 12.04.1 Live, Rescatux, Super Grub2 Disk, or even Boot Disk, which means I'm very unsure of how to repair / re-config the grub record or even fix the Windows MBR and then sort out things from there.

Thanks to other posts, I can find the folder with several dozen *.mod files. So I'm pretty sure I'm in the right partition now (even if it's slightly corrupt or now in the wrong order etc). From "grub rescue>" I typed "ls (hd0,msdos5)/boot/grub" to find this area and this is after the "error: unknown filesystem" response to the other options (Hd0) (hd0,msdos6) etc.

I have to other MAC OSX machines which I normally use, but I can't think how to solve this at all (very limited knowledge of Ubuntu to date). If anybody sees this and thinks they have a possible solution, I'd be really appreciative of the commands or procedure to recover. I need the data on the disk but I am happy to re-install operating systems if needed.

I'm very sure that this is simply down to the partition mod unfortunately but I'm sure somebody will know how to recover this (fingers crossed!)

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Sorry, I meant to say that I have checked the BIOS and the boot order is correct; Optical Drive, Floppy Disk Drive**, Hard Disk Drive in that order. ** aka USB in this case. Network Boot is currently disabled within the BIOS but I guess that may be a suggestion if anyone could enlighten me on the way to do that. – Triple A Oct 14 '12 at 18:02
Please try this.. . Try recommended repair, if this also fails, post the boot-summery info. Though I would recommend a reinstall of ubuntu as we don't what you changed exactly. To get xp working, boot with xp and use fixmbr, fixboot command (plenty of tut on google) – Web-E Oct 14 '12 at 18:19
Web-E Thanks but here's my dilemma! I have read that link before posting and I would love to try this. I have even downloaded and burned this to a CD; The irony is I can't do ANYTHING apart from end up with "error: unknown filesystem" new line "grub rescue>" if I try and boot from CD or USB as well as from the hard drive. That's why I'm hoping there must be another way! I can't post a boot-summery info because I can't get that far at present (if that makes sense?) – Triple A Oct 14 '12 at 18:39
Yeeehaaa! There is always a way! It's all on here: (with patience and careful reading / typing, it's all done and sorted! – Triple A Oct 14 '12 at 21:06
when you use usb/cd for booting.. you must change boot order to boot from the drive. error clearly indicates, somehow hard disk is getting booted first. Anyway, glad you sorted it out. – Web-E Oct 15 '12 at 6:33

Web-E, thanks for your help, appreciate you coming back to check afterwards. The irony is, I understand exactly what you are saying and agree 100% but.... Within the BIOS, you can alter the order that things boot in and I'd already made sure that the HD was LAST, i.e. after everything else in boot order. In fact, so paranoid was I that this was the issue, I did it three times (!) before posting on here, but that didn't make any difference at all. I have no idea why, because it should do shouldn't it?

Anyway, the answer was this section on the Grub2/Troubleshooting page (link above). This maybe useful for others with a similar problem possibly.

Extended Fix:

The following commands should set the root and prefix paths and load the kernel and initrd image. With this information, GRUB 2 does not need a configuration file and should be able to boot the system if the only problem was a corrupted or missing menu.

Press ENTER after completing each line. Some entries will not provide feedback. This is normal.

If a "file not found" or similar error message is displayed while running these commands, ensure you are using the correct X,Y values and the correct paths are set.

  1. set root=(hdX,Y)

Confirm the correct X,Y values and press ENTER.

Example: If the Ubuntu system is on sda5, enter: set root=(hd0,5)

  1. linux /vmlinuz root=/dev/sdXY ro

Example: linux /vmlinuz root=/dev/sda5 ro

If the vmlinuz symlink does not exist, use the full path to the kernel in /boot

Example: linux /boot/vmlinuz-3.2.0-14-generic root=/dev/sda1 ro

If successful, after ENTER there will be a slight delay and no messages.

Wubi users only - substitute these commands in Steps 1 and 2:

  1. set root=(loop0)

  2. linux /vmlinuz root=/dev/sdXY loop=/ubuntu/disks/root.disk ro

  3. initrd /initrd.img

Selects the latest initrd image.

If the vmlinuz symlink does not exist, use the full path to the initrd image in /boot

If successful, after ENTER there will be a slight delay and no messages.

  1. boot

Boot to the latest kernel on the selected partition.

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