What 'noise'? Hmm, the 'drrrr' noise. I do recall having such a problem with an old computer, but the screen went multicoloured and all trippy with loads of vertical bars across it; it crashed. So, here's what I think.

a) It's a hardware fault. A piece of your hardware, which could be the RAM or video card maybe, is causing problems.

b) It's something more than that... something on the hard disk. The way to get past this would be to reformat, but you'll erase all of your data in the process. I think it's worth finding out whether the first one's causing this first.

It'd be great if you could get some kind of photograph... it's just that 'drrr' doesn't cut it.