Ok, so I added a second harddrive to my pc, via SATA.
Plugged it in, formatted it etc., installed programs on it, worked fine
Then, one day it packed up, couldn't see it at all. So I gave it back to the mate that sold it to me, he put it in his pc, works fine. Bring it home, plug it in, works fine.
Turn my computer off, turn it back on and poof it's gone. Taken it out and back in again, still nothing.
Help?