Help:PC restarts frequently CPU Over Temperture Error! ASUS P5GD1 board

Hi to all Major Geeks,
my PC is lately suffering from frequent restarts, rebots or shutdowns
while doing nothing more than browsing web, watching Youtube or
doing a scan with Avast....

sometimes i get message on the startup:
American Megatrends
CPU Over Temperture Error!
Press F1 to Resume
i have opened the left and right side covers of my PC and put a huge room Ventilator on the max pointed right into the CPU.... so its OK for a while but the problem is random....

What is going on..... Avast cannot find any viruses ..?

thanks in advance for any help

vintagefreak
P.S. Intel Pentium 4 3.40 Ghz 1 GB Ram , ASUS P5GD1 Motherboard, Version 1014,001, BIOS Type AMI, Windows XP Pro Service Pack 3

 

Have you ever cleaned out the dust from the inside of your PC? Dust can clog the fins on the CPU heat sink and other parts.
Most retailers sell cans of compressed air for just this purpose.
Instructions:
http://www.bleepingcomputer.com/tutorials/tutorial118.html

 

thanks for reply MAgor Geeks, gotta check my dust levels and the fans..; than will post my results.
vintagefreak