PC wont boot up when 2nd HDD plugged in

RIght, so I just did a clean install of windows 8 on my SSD(without the HDD plugged in obviously) and formatted my HDD, and I fired up the computer But it only got to the windows loading screen, and stood there, Untill i Unplugged the HDD, then it instantly started up to login screen. I have switched around on the cables, updated, and flashbacked the BIOS, switched the MOBO connector the cables were plugged into, checked the boot prority, I've basicly tried everything I know off. And nothing makes a difference.

I know it's not the HDD dying, because I threw it into my dads, computer, and there were no problems then.

My MOBO is the Asus Sabertooth 990fx R. 2.0

HDD: Western digital blue 1 TB 7200 RPM

SSD: Samsung 840 120Gb

Please help, If you have any questions, throw them at me, I'll be happy to answer them if I can. And any suggestions is greatly appreciated.

-FerverdCookie27

Might be the controller perhaps or a bad cable?

Nah, I've tested cables, and swapped the connectors and stuff. Besides, I've run into the problem I firstly wiped it for and stuff, so I'm sending in the MOBO RMA(If you want to know more about that here's a link https://teksyndicate.com/forum/cpu/computer-freezes-cpu-related/182619) Only, now I've had it at a computer technician, I've spend over 30 hours trubleshooting my self, and I've made sure it's not any of the harddrives, the CPU, GPU, RAM or, the PSU, there's really only the MOBO left, so....