X64 Freezing Only After OC

Up until now I've been dual booting with xp and xp x64 and everything has been fine. However I've recently began to OC my Q9650 (full specs below) and now my x64 freezes everytime about 10 seconds after windows starts, no matter how small or large the OC is. My desktop will come up and everything will appear to be loading successfully however after 10 secs I will get the "new hardware is detected noise" (even though no new hardware has been installed) and a second later it will freeze. The confusing thing though is that when I boot up into xp 32 bit, I get absolutely no problem, no new hardware noise, no freeze, nothing. I have played with the voltages a little bit to see if it just wasn't getting enough power, etc. but nothing seemed to change the freezing (and remember through all this, the x32 was still booting fine) Any help would be appreciated and below are my specs: Thanks a bunch!

XFX 780i
Q9650
Dual 8800GTX's (SLI)
4 Gigs DDR2 800mhz