Shoutbox

Pfff, turn your PC off.
Next, open the case, don't touch anything yet
You can push aside wires a bit so you can see the fans.
Next turn the PC on, and check to see if there are any fans not turning.
Be sure to turn the PC back off
If all fans are spinning, go to a PC shop and let them have a look,
if one of the fans is not spinning, check to see if it's plugged in, and try cleansing it.
If that doesn't fix the problem, go to a PC shop too