Q: It does it repeatedly with no real pattern where it just goes black and then back on again every 2-10 seconds. I run regular virus checks so i dont think its that.
A: I think it could be a contacts issue with either the VGA/DVI cable or the power cable, or it could be a graphics card issue. The next time this happens check the power indicator light to see if there's electricity. If the light is off, then it's a power cable contacts issue. Try and push the cable furthur in or tighter. If the light stays on then it could be a VGA or DVI cable problem. Tighten the contacts and see if the problem stops. If it still continues then it could be a graphics card issue. Swap the graphics card in your PC for either a spare one you have or borrow one from a friend for a week and see if it still occurs. If it does not then you'll have to replace the graphics card with a new one. If it still occurs then it could either be a faulty monitor or cabling. Diagnose it by using a spare cable or monitor and see if it still occurs. If it doesn't problem solved. If it STILL occurs then the last reason I can think of is that you're using Windows Vista! LOL. Seroiusly, I won't be too surprised if that's the cause of the problem. Vista's a rubbish OS. XP rules! :-D