windows crashing - hypertransport sync flood problem

msi 770 g45
athlon II 635
 nvidia 460
4gb ddr3  1x KHX1333C9D3B1/2G 1x TED32048M1333HC9
win 7 ultimate x64 ( first time i use 64bit) version 6.1.7601.2.1.0.256.1
some 450w corsair iirc

about an hour after I installed a new hdd ( the old one suddenly ...