In Linux terminology, what would that partition be called? (something like /dev/hda#, where # is a number) if you find that, mount it in your Linux install, and see if you can access any files from it.

I don't want to be the bearer of bad news, but this is why you back stuff up before installing any OS. I had some drive specifications change on me when changing from Knoppix to Gentoo, and I ended up formatting an entire 80GB drive! :O Luckily, I had DVD backups that were recent, but things could have been worse.