there are many known issues with using C1E and speedstep at the same time. basically you arent supposed to be using them both at the same time.

i dont see how C1E can harm anything as all it does is switch multipliers, thats all. speedstep mighta messed with your windows or maybe even your bios. a clean reflash and a reinstall of windows probrobly woulda solved that.

glad the new board is running better then the last, stay away from speedstep