HELP, HDD not showing up anymore

So here's the story.
I am running windows 8 64 bit, and my friends OS crashed so I did some data recovery on his HDD and when I tried to connect it to my main rig his hard drive would not show up anywhere (I know how to initialize and partition drives). The chords were all plugged in correctly as I used the same chords that were plugged in to my other HDD just to make sure. Still, nothing. I tried it on my downstairs computer and the hard drive appeared and I could work with it instantly.
Now that I fixed his computer mine is still left unable to find my own HDD that I un plugged. My SSD still works but my 3TB Segate Barracuda won't work.

This is a huge problem as I only have 5gb of storage on my SSD and rely on my HDD for most things, so I'm kind of screwed at the moment.

When I first got my 3TB drive it did this too, and I did something (that after hours of searching the web, downloading drivers ect I could not remember) that made it appear and work...

Any help is appreciated. 


* my downstairs computer runs windows 7 64 bit

* the HDD appears when I check my BIOS, but won't appear in the storage section of device manager

* YES I've restarted numerous times and checked the connection even more times 

prolly the answer is here[/img]