I recently was trying to figure out how to change the settings in GRUB2, and managed to accidentally install GRUB legacy. The next time I tried to boot into Ubuntu...

"error: environment block too small.
Press any key to continue..."

This error message appears instantly after attempting bootup, even in recovery mode. I have no idea if it is related to GRUB, although it seems likely.

Fortunately, my Windows 7 install still boots up just fine, and I can still boot from the Ubuntu Live CD, which is the only way that I can access the partition containing Ubuntu.

Is there any way that I can fix this? Or would it be easier to just back up my files and reinstall Ubuntu?

Thanks,
Luc