Computer struggling to boot

Im not excaly sure where this should go, but admins feel free to move this post if its in the wrong section. I tried overclocking my computer, and to make a long story short, i couldnt get it to OC, so i restored everything to default, and it still has trouble booting. Sometimes it will boot if i let it sit for like 10min, other times it will if i unplug my second HDD. Does anyone have any ideas?

I was thinking it might be the Power supply..

if you were playing around with overclocking, it's possible that you damaged some hardware, keep that in mind. you should probably doublecheck what you have done to the bios (load defaults perhaps) to make sure you haven't made a setting whilst trying to overclock that is causing your problems.