buy another computer, as a back up - they are cheap enough. then have the problem computer looked at, by hn. if it is under warranty, then it is best to have it done under warranty.
faulty ram has been mentioned. there should be a few ram slots in the computer - easy to pull the chips out, and see how that goes
another idea - partition the hard drive, and install a linux system - and see how that goes. maybe even try and install another windows version (eg xp) on another partition .
I used to have trouble in summer, with a computer crashing (heat) - but i pulled out a ram thingy- and the problem was solved.
whenever i had a problem with the computer, i would use another computer (the kids computer) as a guinea pig - and progressively try to isolate the problem
apart from everything else - have operating systems (programs etc) on one part of your drive - and everything else on other parts of your drive
