Okay, so I'm working on converting a friend of mine from Windows to Ubuntu. We spent eight hours today having fun with Compiz Fusion and getting everything setup for her.
We installed Ubuntu on an external hard drive, leaving her Vista installation intact, so as to smooth the transition process. Since she doesn't need her laptop during the Summer, she let me take it home with me so I could do some of the geekier stuff on it.
When I got home, I tried to boot up, but it told me it had an I/O error while loading the necessary boot files. It did this multiple times. I couldn't load into either Ubuntu or Vista before this happened. I formatted the external hard drive with the intent of reinstalling Ubuntu.
I had thought an I/O error was an issue on the software level. Turns out it meant hardware (I'm a Linux semi-newbie; I don't have a working installation of Ubuntu for my own, although I'm quite capable of setting it up. However, I mostly rely on geek-sense to get me where I'm going). The external drive was overheating. You can move about three GBs of before you hit an I/O error. This means I can't reinstall Ubuntu. Or GRUB.
I'm getting another external drive tomorrow. I'd still like to get into Vista though. My friend isn't especially tech savvy (though the potential is there) so she has a cluttered desktop and lots of startup items that she doesn't need and dearly hates, and I'd like to clean things up for her.
So, in summary:
1. Computer tries to load GRUB from external hard drive.
2. Computer can't. External hard drive doesn't work.
3. Cannot boot into recovery mode to get rid of GRUB.
4. I have a LiveCD.