I got the same problem just a month ago. I did 3 things:
1. Go to Control Panel, and System. Then choose "Startup and Recovery" tab. Under "System Failure" you can see "automatic restart". Untick it.
2. Make sure you have the right memory setting in BIOS. This was my major problem, make sure it is 133, 100, or 66 depend on your memory stick
3. In BIOS, there is option like halt on error -> choose none.
I hope it helps, it will be nice if you can tell the rest of us whether the suggestions are good, and how u fix the system. Thanks