computer over heating

Check to see if the fans are blowing, also check the path of air and remove obstructions if the fan(s) are blowing. If it continues, then replace the power supply. If a fan is dead, replace the fan, but if the fan on the power supply is dead, immediately replace the PS.

If you have added memory, drives, or a large video card, your power supply might be too small for your needs, and is having to work at it's maximum limit too much of the time.

While a 250 watt power supply used to be enough, with the latest CPUs and CD burners, you need 400 to 500 watt power supplies to run all the hardware safely.

Check if the air inlets on the front and back of the PC are blocked with dust.
If so, clean out the dust, and consider installing a case fan set to blow air into the case.

Chas

Most likely your ps fan. They are standard 80mm fans so there easily replaced, just stay away from the capictors which pack a lot of voltage.

Over heating issue on a system of reasonable short age can also be caused by inadequate ventialation. the high volume harddisks of today generate sufficient heat to easily heat your system. if the system is working and not shutting down you can increase cooling and performance by:
1) install pancake fans on front and bottom of harddrives over 20gb
2) install memory cooling fans on ram arrangements
3) install additional cabinet fans
4) wire tie all cables to increase airflow ventilation throughout cabinet
5) clean all colected dust in and around fans and boards
6) increase the cfm volume of the cpu fan with larger cpu fan.
7) added memory heat sinks to video memory
8) replace case and power supply with heavier duty power supply.

I have seen way to many systems that have been improperly diagnosed as power supply problem when in fact the powersupply is only being overloaded by dust and debris and system components drawing extra power due to improper cooling.

regards
rick

thanks so much for all the help!!!