I have a friend who assembled a computer about 2 months ago and installed Need For Speed Most Wanted. Recently the OS has become ver unstable. He gets the blue screen and the machine restarts on its own. What could be the problem? The computer has 128 MB memory, 40 GB HDD, 2.6 Intel Celeron processor, Windows 2000 (no service packs) and a 128 radeon graphics card. The harddisk is partitioned into 2.