When I installed my RAM into my motherboard, my motherboard set the RAM timings as 6-6-6-16 and the voltage at 1.5V and 1066mhz, When infact my RAM is rated at 7-7-7-21 at 1.6V and 1333mhz. Motherboards are pretty poor at setting voltages and timings
Another example is my motherboard set my Core i7 920's voltage at 1.28V, when its able to run stable at just 1.10V.
I've never heard of that powersupply and apperantly neither has Google (0 results found).
So if i were you i'd do the following
1: Set the correct Timings and Voltage for you RAM and CPU.
2: Get a Good quality PSU like a Corsair 550HX or a OCZ ModXtreme.
3: In the morning start OCCT CPU test and then go to work, Assuming you have a 9 till 5 job when you get back it will be done. (don't worry, if it fails or gets to hot, it will shut down the program).
If OCCT runs for 8 hours with no errors then its pretty safe to assume that your memory, motherboard and CPU are stable (and not the cause of the problem). Then its either the Game you play ( for example My PC is stable, but Fallout 3 crashes from time to time, but no other game do this.) A Video driver, Graphics card stability OR your PSU isn't up to the job. I think the latter is the cause to be honest.