Need experienced help! Why does my computer restart randomly?

[haut]

About a week ago I had a huge problem with my computer where it would restart itself within a minute or less of starting up and I couldn't control it. I tried a new video card, same thing. Tried a new power supply, same thing. Tried a new motherboard, its gone. Now about a week after that mess my computer resarts now periodically. I had left it on when I left today and I came back and it had restarted. Then later it restarted again (a few hours later). Here's what I have:
Mobo: (old) epox 8k7a (new) DFI AK76-SN
CPU: Athlon Tbird 1.33 ghz
RAM: 512 MB DDR
Video: MSI Geforce2 Pro GTS 64mb
Sound: TB Santa Cruz
Case: Enlight 7327 w/stock power supply
NIC: generic CompUSA
HDD: IBM deskstar 40GB
OS: WinXP pro
Thanks for any advice!
--Ryan

 

[Kelvrick]

What are your system temps? First thing I thought of.

 

[haut]

My current CPU temp is 51C and the overheat temp was set to 50C on the program. I changed it to 60C for now, just so I dont have to worry as much about it. My computer has only been on for a little over a half hour so I'll keep an eye on the temp. The CPU Hysteresis temp says 40C, whatever that means. The system overheat temp is 50C, system hysteresis is 40C and current system temp is 29C. My CPU fan (thermaltake volcano 2) is at 5080 RPM. If any other info would help, just tell me. Thanks for replying!
--Ryan

 

[haut]

Does anyone know? Thanks.

 

[Kelvrick]

Your temps seem ok, I guess. Have you tried a reinstall of windows? It could be currupt installation or viruses.

Correct drivers? IRQ conflicts?

 

[noxipoo]

disable auto restart on error first,

to do this, right click my computer, properties, advanced tab, settings under Startup and Recovery, uncheck the box taht says Automatically restart under system failure.

now when it reboots maybe you will see an error msg

if it doesn't show anything, just reinstall windows from scratch.

 

[AndyHui]

Please read the FAQ: Why does my computer restart itself?

 

[Duvie]

I agree...first make sure winxp auto restart on errors is unchecked...this way if it is an error we commonly see as a BSOD you can see what the problem is...

second if that is not it....it may still be a temp issue...I know what you said....all socket a amd boards are notorious for varying and incorrect temperatures...dont put all stock in faith in them...

third...if ocing anything, stop and set all bios settings back to default....