problematic problem (fin allow)

When my mate is playing ET, his computer shutsdown every time when he had played more than 5minutes. Other games are running well and without problems, he has also tested most of his computer parts, which would cause the problem. He has also made format C, so it ain't working yet.

Any can advise him?

system info:
Mainboard : MSI MS-7380
Chipset : nVidia nForce 750i SLI SPP
Processor : Intel Core 2 Duo E6850 @ 3000 MH
Physical Memory : 2048 MB (2 x 1024 DDR2-SDRAM )
Video Card : NVIDIA GeForce 8800 GT
Hard Disk : SAMSUNG (160 GB)
Hard Disk : Maxtor (251 GB)
DVD-Rom Drive : PLEXTOR DVDR PX-740A
Monitor Type : Samsung SyncMaster - 22 inches
Monitor Type : Samsung SyncMaster - 22 inches
Operating System : Microsoft Windows XP Professional 5.01.2600 Service Pack 3
DirectX : Version 9.0c

and heats are normal.