I'm a huge fan of Norton Ghost. I'd say, ghost (image) the disk to another drive, unplug the original, and do whatever you want to the copy. Reinstall, repair, experiment, etc. on the copy. Then worst case scenario, is that you would just plug the old, broke HDD back in. It wouldn't be fixed at that point, but at least you won't be worse off...
Knoppix is also key in many ways, and one of them is data recovery if you don't have many choices
