Pc resetting whilst gaming

[cotters]

Ive had a problem recently where whilst playing a game my pc would just reset. I thought straight away it was overheating but monitoring the temps and nothing goes above 80c cpu or gfx. So now im at a loss as to what could be the cause as all the hardware except the case and psu are under a year old.
Specs:
Intel i5-2500k @ 3.30ghz
asus p8z68-v lx
corsair ddr3 667mhz 4gb x 2
Nvidia geforce gtx 550ti

Any other specs needed just ask.

I recently put in a new hard drive but i tested that for errors and found none. Could windows cause it?

 

[jaguarskx]

What power supply (PSU)?

If the all the components demands more power than the PSU can provide, then you need to buy a higher wattage PSU.

 

[cotters]

Its 500 psu. Im considering ordering a new case and psu. And hoping the new psu and better ventilation from the case can atleast rule that out.

 

[Brett928S2]

WHICH psu ?

 

[blacknemesist]

There should be rules for this type of thing.
You monitored the temps using what software?
Which software was used to stress the CPU?
Which software was used to stress the GPU?
For how long were those software running for?
Are the games legal or downloaded?
Which version on drivers are you running?
Did you try to upgrade your GPU drivers?
Which PSU brand and model is it?

 

[cotters]

Im using HWmonitor
I used heavyload to test cpu
I used furmark to test gpu
HL was running for around an hour. While i just did the benchmark for furmark which was 15 mins at 99% load.
Games are legal.
I checked and the drivers were all updated.
The psu is old around 3 years, its a sumvision by the sticker 500w thats all information it gives.