I got an intermittent boot issue with my PC I'm running Windows 8.1 and a Intel Motherboard DQ67SW AAG12527-306 with i7-2600 3.4GHz processor, when my PC has been switched off over night the next morning when I start it up, it powers on, fans start, goes into post start then it shuts down before Windows boots, then tries to start again by itself, sometimes it will boot correctly the second time or could be the third time. Other times Windows will load ok but as I try and log in it shuts down. The motherboard does not give any audio beeps when booting or during any booting failures/ issues. But once my computer has been running for a while I can shutdown or restart the computer as many times as I wish and it never fails to boot. I have replaced the power supply, changed the memory, removed CMOS battery and reset, upgraded to the latest 2014 BIOS firmware for this motherboard. formatted the hard drive and reinstalled Windows, I am thinking it must be the motherboard there is nothing else left?