If you have plenty of stuff you wanna keep, your best bet would be to install an additional copy of Windows as a testbed to ensure everything's stable. If during the installation things croak, or if the fresh Windows still bugs out, then we're dealing with hardware. Again, it seems coincidental this is happening far more often with the new CPU installed. You may wanna check to see if the CPU has been installed properly, that no pins on the socket nor the CPU itself are bent or broken, and that you will want to reattach the heatsink to the CPU. When doing so, make sure to apply a fresh layer of thermal paste, removing the old stuff first.

Btw, do you know exactly what the bugcheck codes for some of the crashes are? They're the number outside those in the parentheses. If you can get me the first two numbers in the parentheses two for some of em that'd be great also.