Looking for a device to Stream movies from my PC to my TV

there really is no such thing for $100, but spend a bit more on a good video card that will plug into your computer that will include an HDMI output.
Then you can plug the computer to the HDTV, and watch streaming, downloaded movies and DVDs maybe.
Depends, if you have a single core processor, you will probably not get the video quality that you hoped for. If you have a dual core and run the minimum amount of programs, you can get decent video. Too many programs running on a dual core can still gum up the video playback. A Quad core is more like it, because you can run lots of programs and video too.
In any case, it might be a good idea to run 3 GB of RAM memory in XP or 4+ GB in windows 7.

I dont have a wire that can go from my basement to my living room, otherwise i would hookup my computer via hdmi. I think this will do the trick: http://www.newegg.com/Product/Product.aspx?Item=22-136-...