Sort it by size and go down through them, and look for a bunch of files probably of a similar size, similar/random name, and in a folder that you don't recognize. Or maybe just one really big file even.
If you find files like that, you should be able to just delete them. Just don't empty the recycle bin til you're sure they're worthless files.
E: Or if you know what the name of the trojan was you could just look up what it does to see if there's instructions on how to clean it up.
This post was edited by downloads_plz on Oct 1 2010 10:50am