Im not sure what is wrong with my computer...
 

it could still be heat... try opening up the case and seeing if it screws up again

yea i opened the case and have a full standing fan blowing in... still does it :/

Have you tried it with another monitor? I've seen monitors that are going bad put up solid colored lines across the image. Also, you're using an analog display, so it could be a bad DAC.

my grand fathers computer does the same thing, its got me stumped...

i just figured it was something wrong with the motherboard