Fried Green Computer?

Ok so...

I don't know too much about computers other than how to run them...so you'll have to excuse me. My computer is not working and I think it may be gone forever, but I figured I'd ask someone who actually knew more about them.

First my roomate told me that the computer would not turn on and it smelled like smoke. It turned on just fine for me so I didn't think much of it, but it was running very slow. Being that I've encoutered slowness before I figured I'd run it through HijackThis to check it out...there was some stuff on there, but it was pretty clean compared to what I've seen before. It did run a lot better afterwards so I thought I fixed it. Later when I went to turn it on it smelled again like burning and the screen had verticle stripes across it...first blue than red and white which started flashing until the screen just shut itself off. Nothing else came up, just the stripes. I have no idea what may have caused this...if I may have messed it up or if something else is wrong...is it fixable? Anyone?? thanks for your help!!