Video problems - Kickes, Reboots, Freeses running 3D-Graphics

Cannot run anything 3D-graphic for a long. It kickes me to Windows in 15 mins or in an houer. Sometimes. but seldom comp reboots and even more seldom it freeses.
It looks like Video card problem, but I used it before in other system and all was fine. I also thought it was CPU temp. prob, but CPU temp was normal every kick/reboot/freeze. It is also not Win XP problem b/c I get the same result in WinMe.

System:

MB: Gygabyte GA-7VR (KT333)
CPU: Duron 1,300
Video: Albatron GF4 MX 440
Others...

Any suggestions?

 

When you say it won't run 3D programs what do you mean? Games, graphic programs or other? Do you have the latest drivers for your video card?

 

I mean they run for a while, but after 15mins - houer of running program is closed or computer reboots.
I don't work with any 3D graphics nongames software. The comp runs any 2D programs fine (I work up to 12 hrs with Flash MX).
So I can tell only about 3D games. They crash badly. I tested even oldest ones (wich use 3D acceleration) like X-Tension etc. all the same!

Oh yes I setuped all lastest drivers for all hardware I could find.