My computer keeps dying

[Jangle]

Every so often my computer freezes, then a few seconds later the monitor turns off and then my computer resets. It didn't used to happen very often but now it happens maybe four or five times a week. I'm not sure if it's overheating but I put in a second fan and it doesn't seem to have fixed it. I also got rid of all the dust and stuff in there. Does anyone know what could be causing this and how I can fix it?

 

[-Psy-]

CPR CPR CPR!!!

Ahem. Tried updating all your drivers?

 

[xombine]

Specs? How old is it?

 

[Jangle]

It's about two years old. I've got an athlon 64 3000+, a 128mb radeon 9800 pro, 512mb of ram, 160GB hard drive... I recently bought a new PSU because somebody suggested that might be the problem, but it didn't help.

 

[The Brick]

Do a check with memtest.

 

[Raziaar]

When I got that issue a long time ago, it was due to a failing power supply.