why does my computer lock up and restarts itself?

[TaintedKiller]

Why does my computer lock up and then restart when I am playing a game? I've had this problem for 2 years now and still can't figure out why. It locks up almost everytime when I am playing a computer game. When I received my Pentium 4 3.0 GHz, I did not find any thermal paste but on the top of the box it says with thermal compound. Does that mean I don't need to worry about putting thermal paste?

system specs:
Pentium 4 3.0 GHz (52 to 68 degrees)
512 MB RAM
80 GB Maxtor
Radeon 9600 256 MB

[Darkstar]

Their should have been some paste or most likely a thermal pad stuck on the bottom of the Heatsink.  If there was no pad or paste then that is your problem.  68 degrees C??  looks like too much to me.  Is that under load or idle.  Under load it will go up.

Check your ATI temp also....Games(3D) will push it to the limit if they are recent 3Dgames.  Video drivers may also be the problem.   What version drivers for the 9600 you have??

[Raptor]

What type of Power Supply Unit is intalled?
Do you hear any beeps?

Pentium 4 3.0 GHz (52 to 68 degrees)

Awfully warm for a Pentium CPU. You should look into more adequate cooling.

Cooler Master is an excellent brand.

[TaintedKiller]

How can I find out if there's a thermal pad stuck on the bottom of my heatsink?

I use a 350 watt power supply by Antec. And yes, it reaches around 68 degrees after running current games like Doom 3 and Half-Life 2.

I used SpeedFan to check my volts, and I don't think it's a power supply issue but it looks like my CPU is overheating. Here is a link to my results. http://img139.imageshack.us/img139/7734/speedfan2dr.gif

[Darkstar]

You will have to remove the heatsink from the cpu and look at the bottom to see it the pad is there.  If there is nothing there on the sink or cpu, then order some artic silver paste and apply it to the cpu\heatsink.  Look at this link to see what it is...

Here;
http://www.newegg.com/Product/ProductList.asp?Submit=Go&DEPA=0&type=&description=artic+silver&Category=0&minPrice=&maxPrice=&Go.x=2&Go.y=26

[merlin_2]

http://www.cpuidle.de/