Hey i have a 550W PSU not a 750W can this be the problem? this is my PSU http://www.epowertec.com/ep550xpf.html
I don't know the make and quality of your power supply, but if it is supplying what it promises 550w should suffice.
I note your memory is Kingston and they make a good product.
I want you to try the following: Take off your side panel, have a small fan set on low blowing into your case and then play one of your games. Does it crash?
Okay, let us diagnose this by a different method:
1. Download Driver Cleaner Pro (free version; if running a 64-bit OS substitute with Driver Sweeper) to your desktop screen and install.
2. Download the latest diver(s) for your video card but don't install them.
3. Uninstall your video card drivers and reboot your PC into Safe Mode. Run Driver Cleaner Pro. If it doesn't find any video card drivers that is quite okay.
4. Reboot and install new video card drivers.
Did it but still shuts off. on the xfx website they say the xfx geforce 9600GT needs min. a 600W PSU with a 6 pin. i have a 550W PSU and two 4 pin going into a 6 pin in my 9600GT. can that be the problem?