My friend and i decided to swap psu as i was doing him a favor because mine is a modular so it looks better in his perspex case. Well i took his coolmaster 850w psu and pulged it into my system and i wouldn't boot into windows. Well after checking my bios everything was in order accept the first HD boot .... it was pointing to the wrong HD with no operating system on it as i have 3 HDs in my PC. Anyway i got it going it the right way but got blue screen before windows. I found out that i had to unplug all the other HDs and only leave the one with the OS to get it booting into windows and so after that i replugged the other HDs and all is fine now boy was i lucky ..... I want to know why has this happened ????? Well here was what happened to my mate. We plugged in my psu for his asus striker and couldn't get into windows .... so time to check bios .... what we saw made our hearts skip. Damn voltages were running MAX thats right 1.9v for cpu and max for everything. Well after resetting things it looked fine in the bios but still we couldn't get it going. Then we decided to run system check ...... turns out none of his HDs were showing. 2 X 150gb raptors in raid mode and a 500gb storage. So we pulled the HDs out knowing what happened with the voltages and looked the back of them .... yep they were cooked ..... All data lost and some expensive HDs to replace. So anyone has something similar like this happening or knows what the problem is ???