Computer crashes when starting any game

[Angramar]

So I started out with a HP pavillion G5130 which i bought 2 years ago. I was getting really annoyed by the low graphics performance of this PC so i bought a new videocard and PSU, now the computer runs all programs like word and chrome etc smoothly, but whenever i start a (newer) game it crashes immediately. I really cant find the problem,so i hope you guys could help me out.

specs:
CPU Type: DualCore AMD Athlon II X2 220, 2800 MHz (14 x 200)
Motherboard Name: Pegatron 2A99
Motherboard Chipset: nVIDIA nForce 6100-4xx, AMD K10
OS: Windows 7 64-bit
Video card: NVIDIA GeForce GTX 560 Ti Hawk (http://nl.msi.com/product/vga/N560GTX-Ti-Hawk.html)
video card driver: nVIDIA ForceWare 306.97
PSU: Advance 650Watt (http://www.rueducommerce.fr/Composants/Alimentation-PC/Alimentation-non-modulaire/ADVANCE/2957247-Alimentation-ATX-thermo-regulee-650W-ventilateur-12cm-Tuning.htm)

If you need any more info about the setup, please let me know!

 

[silliconcrayon]

do some benchmarks first ... keep an eye on temps .. and is that brand of your PSU ? "Advance " ? never heard of it before .. most preferred brands are Antec , cooler master, seasonic , corsair ..and you better check out weather your GPU gettin enough power .. run some bench marks ..connect the power cables properly into your GPU ..also check for your CPU paste and temps