Just go to download.com and look in the video section, or search for video editors. If all you have is Movie Maker and you just want something to mess with, then there are a few on there that should work.
Otherwise, although I hate it, Premiere works. FCP is definately the way to go... if you have a MAC, and I wouldn't suggest having a mac for any other reason, because they suck for general use, the have to be specific, you have much more freedom with a PC even if they do have more problems.