This probably isn't any help but anyway...
My computer was getting slower and slower until it stopped working. When I tried to turn it on, it would get to the black screen with a few words and then restart. I couldn't fix it to I took it to someone I knew who could try and fix it. There was some clash between my graphics card and Windows SP2.
So yeah, it's all good now.
Hopefully you can fix your problem
/ 
