IRQL errors are usually either one of two things:
A: Driver Conflict (Unlikely due to Windows Re-install)
B: Bad RAM
Run a memtest and rule out the RAM before you do anything else.
QFT - Double check that your memory settings are proper and as specified in the manual - If you have the option, please set the voltage to the upper end of the recommended range. If you've overclocked, Un~do it, then troubleshoot, then re~do as necessary.