need help with my pc

[jontcold]

i just buy a new pc amd phenom2 x4 965 3.4
with m4a78 pro board and 1066 hyper x went i put in the bioa 1066 my pc crash some one told me to put my mem voltage higher thx for reply my memorie khx8500d2t1k2 4go kit

just mentione i start windows without problem crash when playing or ramdom crach when i set at auto no trouble but it set a 800 mhz and that suck