A few years ago I bought a computer and have been upgrading it over about 2 years. I have a bit of knowledge with computers but I am having a bit of trouble with it now. I upgraded the video card to a Gigabyte GTX 660 Windforce and processor to an Intel I5-3470 3.2 Ghz. Before I got the processor I used the gtx 660 but my computer kept locking up (everything would just stop but the computer would still run) and I always needed to turn it off by holding the power button. I thought it may have been the video card so I swapped it back for the old one I had (GT 630) and waited till I got a new processor, thinking that may fix it.
I am at a loss now though as it still crashes every so often with the new processor. I checked the temperature of the CPU and the video card and nothing is wrong. they don't overheat before it locks up, nor does it show any signs of it doing anything to cause it. it also seems to be random as it crashed on a game once but after a reset I could play the game with no problem.
CPU: Intel i5-3470
RAM: 2 X 4GB DDR3
GPU: NVIDIA GeForce GTX 660
OS: Win 7 Ultimate 64bit