System restarts or hangs on playing games

Can you tell us more information about your system please. In particular, details about your PSU are important.

A system that is restarting probably has power problems. Simply hanging could be that, or drivers, heat, or any number of other things. As RIP said, we will need more information about the parts in your system. CPU, GPU, RAM, and especially PSU are all important. Does your case offer sufficient cooling? Have you blown the dust out of the heatsink(s) and fan(s)?

i have a board named consistent I945LM4 with a PCI express slot, 1 GB 800 Mhz DDR2 RAM, intel P4 2.60 GHz, FSB 400 MHz L1 cache 8KB L2 cache 512KB , PSU Necola 450 W and i added an extra fan for cooling.
using Win XP as operating System.
in my earlier PC it was an Intel original D845GVSR board, 512 MB 333 MHz DDR1 ram, NO PCI slot, no extra fan, PSU mercury 300 W. when it crashed i replaced all the above things except Processor.
one thing i suspect is that my processor is of 2.60 GHz and cpu's frequency shows inside bios is 3.46 GHz.
it run very fine no flick in sound or graphic, but if i run any game (no matter how simple or heavy it is) it will sure hang or show BSOD with massage code within 1-4 minutes :
*** stop:0*0000008E (0*0000005, 0*0000000C, 0*AAF4FACO, 0*00000000)
some time it also happens when i m surfing on net and running many applications, listening music.

What temp is your chip running at? Do you have any parts to swamp out and test? Could be heat, memory etc.

I find it interesting you carried the CPU over from your previous machine that was crashing and that it's running at some strange frequency. Can you manually set the PU to run at 2.6Ghz and see if it helps?

problem started from very beginning when i assembled my new parts and was installing win XP, it started hanging even on formating and file copy screen or even on bios setup. but after xp installation games were running pretty good except an error massage that shows "system has encountered a serious error has to shut down." but after few hours of game play.
then it started in very short time interval and totally freeze the system or BSOD. today i formated the system and installed new windows to make sure it is not a virus, problem continues. today it gives BSOD and a massage there :
ALCXWDM.SYS - address F702930B base at F6ED4000, datestamp 42e5fc56
that indicates the sound driver, i tried other copies of driver but no results.

Manually reset the BIOS to defaults using the jumper on the mobo. At stock, the BIOS should recognize a 2.6GHz CPU as such and run it at that speed.