I need helps

I have done all the trouble shooting steps that I know and do not want to have to fix computer with a 12 gauge.I have check all the connections inside and outside of the case (gpu power cord etc),memory diagnostics for the ram sticks both in then one at a time, updated all driverd in device manager,put three different gpus in, and checked sleep settings.My computer is hard hanging it happens at rambom moments and the time frames vary it usually will hang when I watch videos or play video games but it hangs when ever it feels like it.Getting a event 41 kernel power not sure what it is though cant figure out how to set up dump files to clue me in on whats happening I'm new to 7.Cooling is shouldnt be a problem though that is why im confused.The cooling should be great 120mm sealed water cooler cpu (tubes feel coul when touched),2x 80mm fans on top,80 mm in the front PSU has a fan in side the psu case creating a push pull,120 side case fan pointing at gpu.Help would be appreciated befor sink some money into a new mob and psu (suspect bad pci slot where gpu is plugged in at but not sure usually they dont when they break this one will display).If you need dump files for further trouble shootin I'll need help setting them up so they can be created.Nothing has been Over clocked.....yet

System sprecs
CPU:amd 1100t
GPU:nvidia 550 ti
mobo:Asus M4A87t
PSU:480 w
OS:windows 7 home
HDD:7200rpm 750GB 64MB cahe
RAMDR 3 2x2gb
and some type of dvd drive really dont pay much attention to them

Never mind figured it out Bios needed to be updated manufacture installed a newer graphics card than the motherboard and didn't update the bios.....go figure.