What's the problem when computer stalls and starts to beep continuosly?

Someone said might be processor heating over the value given in BIOS. I had 67 celsius and disabled it, but thing still happens. Haven't touched the bios more.

This occurs evrytime when I try to play 3d-games such as operation flashpoint or combat mission 2, and sometimes when rendering animations.

machine:
AMD 1,4GH, Asus7a266 (iirc), CLub3d radeon 9500 pro, 512 ddr and XP pro.

Thanks in advance,
ukas

From what you're saying it indeed looks like it's a temperature problem. If your PC reaches 67°C while playing 3D games (which use the CPU more intensively than other games) I would look at a way to upgrade the CPU cooling...
I'm running an AthlonXP 1800+ at around 55-60°C, with CpuIdle installed.

Also, check the manual of your motherboard, it might contain a chapter with the beep codes explained.