So, I am a complete overclocking newbie. Read up around a bit and gathered the courage to try it out. I even found and followed to the letter a guide for overclocking the exact same motherboard and CPU combo I'm using (http://www.tomshardware.com/forum/263043-29-1156-core-core-overclocking-guide). To start out, i tried out what they say on the guide should be a very easy and safe overclock of 3.6 GHz. Sadly following that guide failed miserably, my PC wouldn't even start BIOS afterwards, it would just stay powered on for a few seconds, then shut down again. After resetting the CMOS, I tried doing the exact same thing again, except only doing a tiny 20x 150 overclock, with the same settings, and voltages of the higher overclock. Same thing happened again. I even tried doing the light overclock at the maximum voltages stated in the guide, same problem. Is there something extremely obvious I'm missing, or is my CPU sort of unable of being overclocked because it has a few years under it's belt already? Also, my PSU isn't exactly as powerful as recommended for my system, but from what I was told, it is of a higher quality than most brands, and thus it can get away with being a bit weaker (don't understand the logic behind that, but indeed it never failed me all these years). Could that be what's causing my overclocks to fail? No power to spare from the PSU? PC specs are: Gygabyte P55A-UD5 Motherboard i5 750 @ 2.67 GHz (4 CPUs) 2x4 GB DDR 3 RAM sticks, 1600 frequency, timing 9 9 9 24 If PSU specs are relevant, let me know what info you need, and I can look it up on the sticker. Thanks in advance for any help!