[4 High]

So i have an old VPR from Best Buy from 2002 or so, it still runs good, but recently i have had some issues. Its been overheating like whoa recently, and will randomly shut down at times when too much is going on. So i figured i would get a can of compressed air and clean it out. The day i planned on doing that, it seemed like it crapped out. Usually it will overheat and turn itself off, but leave the on light on, if that makes sense. So i turn off the power switch in the room for a few minutes and turn it back on and the computer would work for a while again. However the other day, it shut itself off again. We did the same thing with the restart, but now Windows tells us it was shut off improperly last time and asks how to start. I choose either last known good settings or start normally and it starts up, but midway thru the start up cycle it flashes for like 1/2 a second a blue screen, the only word i can really read is hardware (It doesnt have text like the usual BSOD as i know it) and it restarts itself. It wont get past this part of the cycle. So now i am torn on what to do.

Some background notes...

We usually leave the computer on for days at a time
It is really dusty.
I cleaned out some dust using a paper towel, didnt seem to do much.

Any thoughts?