This a Windows Problem Or System Stability??

[lettuce]

My current overclock, i have done:

20 passes with LinX
1 Hour of OCCT
Primed for 9 hours

Yet i have had my system lockup on me, baically i wont be doing anything stressful just browsing the net, then all of a sudden, all the lights on my keyboard and mouse will go out, and the system locks up. My system must be stable as ive passed LinX etc. So is it a windows 7 corruption fault, due to me finding my stable OC??

 

[lettuce]

Ok guys thanks for the input. Another thing i have noticed aswell is that my user name and passwards for forums doesnt keep me login in after a systems lockup, like with this forum, i have to enter my details all the time, even though i tick the box for remembering my login details, which is why i thought/think its a windows issue not my overclock. I dont see how my system could be stable under stress from Prime (blend) for over 9 hours but not really be stable when it comes to do less stressful stuff.

These are my current voltages:

Vcore 1.268
QPI 1.275
IOH Core 1.14
CPU PLL 1.3
DRAM 1.640

to be fiar i was dissapointed that i couldnt get them any lower, especially the QPI, oh and i do have LLC enabled, is it best to have ti disbaled then? Also what about the power saving features, i have them all enabled apart from the C states