as far as i know, a lot of ppl got the same problem with me with the 3-D game hang. everytime it happened, the pc stops responding and screen freezed, but it is only at the time i play some 3-D games, the system dump is showing that the bugcheck is "The computer has rebooted from a bugcheck. The bugcheck was: 0x000000ea (0x865b1b38, 0x8695fd20, 0xf7a53cb4, 0x00000001). A full dump was not saved." this message ,accoding to MS official site, is due to the display video card driver programmed badly and make the system into infinite loop. i have tested the prime95 for memory for up to 19 hours no errors, so i feel if the cooling is good, it will not be the memory problem but the V-card driver. also i suspect the via 4 in 1 drivers, since i find a lot of reports about this error, regardless it is a nv or ati card, seem all via chipset range from kt333 until kt800**. hope you can find out some solution.