irq not less then equal usually means ram related issue or theirs a problem with the north-bridge controller on your motherboard.

IRQL_NOT_LESS_OR_EQUAL error in Windows 8 is displayed in Blue Screen of Death (BSOD). Just like other Blue Screen of Death errors, IRQL_NOT_LESS_OR_EQUAL error also arises due to corrupt software application files, corrupt system files, incompatible or inappropriate device drivers, corrupt device drivers, faulty hardware devices, etc.

Typically IRQs are the interrupt requests that are sent to the microprocessor via south and north bridges. If IRQL_NOT_LESS_OR_EQUAL error occurs, chances are that an issue with the application or driver is related to the memory or interrupt request.

For Driver irql not less then equal it could be hardware overheat... It could be the card somehow got dislodged from the slot (reseating cards in the case sometimes fixes issues) I have personally had a video card some how come up out of the pci e slot just enough to throw windows into a shit fit.

It could be corrupt system files.. Or a in comparable program or a conflict between a virus scanner and the program itself..

you can also try a manged start-up and disable all the apps on start-up and try it if that works re enable apps tell you find one that causes it..

clean install of windows and reload can also help.