I've been running ubuntu warty warthog for a while now and reinstlled windows because I had to have counterstrike. Anyway, doze overwrote my mbr and now I can't boot back into ubuntu. How can I reinstall grub from a knoppix live cd? I've tried mounting my ubuntu partition and doing a chroot to it and running grub-install, running grub manual and doing root (hd0,2) setup hd0, as well as just about everything else I could think of. none of the posts i've found on linuxquestions have been any help.

when I run grub and try to fix it the way various posts say to, I get this
grub>
root (hd0,2)

Error 21: Selected disk does not exist

*note* my linux distro is on the 3rd partition of my first disk
help?

Via the CD, you need to reinstall/repair. Or you could boot from your rescue floppy and re-execute grub.

have you actualy done this or have any reason to think it is possible? the ubuntu cd dosn't seem to have any sort of repair mode and there is no way in hell I'm reinstalling it. I don't have a rescue floppy for the system. How can I reinstall grub from knoppix? I've done it before on this exact system last time I installed windows. can anyone link me to a tutorial or instructions?

I have done this on many distro's. I have not done it on Ubuntu. When you reinstall, it should find the pre-existing packages and just do a minial install and set the MBR at the end. You reboot and you are done. There is no risk since you can't get to a damn thing anyway.

so, what exactly is it going to do? overwrite my kernel with the one on disk? how much is the "minimal" reinstall reinstalling? can I skip straight to the grub thing from expert mode on the cd?

My don't you let it mount the partitions, then ALT+F2 into a new shell and execute GRUB from there?