steve - 10:26 am on Apr 13, 2005 (gmt 0)

I have one simple (must be cheap) fan at the bottom back of my PC

Is it blowing air into the case, or extracting it?

It should be blowing cool air into the case, if not turn it round.

My PC is very new and I wouldn't want to believe there's a problems with it

Faults are more likely to occur with new equipment. Once its 'run in' faults are unlikely, as it gets older faults become more and more common - its called the bathtub curve.