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I managed to break my installation of Ubuntu. The system crashed either while trying to adjust partitions or adjust the boot order (while in Windows) - not sure which as it was a while ago (the system is set up as dual boot, but also had an old version of Ubuntu on another partition that I was trying to remove to get back the memory).

Since then I've been unable to use the system at all as it had no screen (previously running on an external monitor which only works after boot). Now I've fitted a new screen I see that I have the grub rescue> prompt.

I've tried booting from my Live CD, and tried burning a new one just in case it was corrupted but I still arrive back at the grub rescue> prompt.

I've also tried following the instructions in Grub2\Troubleshooting with the following results:

1) ls gives me (hd0) (hd0,7) (hd0,6) (hd0,5) (hd0,3) (hd0,2) (hd0,1)

2) ls (hd0,7)/ gives me error: unknown filesystem., as do all the other filesystems.

3) Trying other commands to see what was available I found that most give Unknown command with the exceptions of insmod, set and unset. They return:

grub rescue> insmod
error: no module specified.
grub rescue> set
prefix=(hd,8)/boot/grub
root=hd0,8
grub rescue> unset
error: no environment specified.

I know there are loads of other questions on this topic on this forum and I've read and tried the advice on many of them but I don't know what I'm doing wrong. They all seem to assume that step 2 above should set me on the right track.

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Nevermind. Windows Recovery CD seems to be doing the trick, so long as I can find my product number. –  Jamie Bull Jan 18 '13 at 18:17

1 Answer 1

Booting from the Live CD will give you many more options to restore or recreate your GRUB configuration files. I believe this will include the grub-* programs or update-grub2.

I've tried booting from my Live CD, and tried burning a new one just in case it was corrupted but I still arrive back at the grub rescue> prompt.

The fact that your Live CD boot does not work implies your BIOS settings are set to check your HDD before your CD/DVD drive. I would enter your BIOS and check the "Boot Priority", typically found on the Boot Tab.

Also, many BIOSes I have seen, especially in the past few years, have a "Boot Override" selection in the Save & Exit Tab. You could try to force the BIOS to boot from the Live CD using this method.

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