Sounds like, given the lack of details, that the HDD came disconnected somewhere between your friend's place and yours. If you don't know how to fix this yourself, maybe you should invite your friend over to fix it.
Alright, so I recently went to a friend for help installing a new motherboard and processor, it all went well. I went to pick the computer up, he had shown me it worked and everything at his place. I got the computer and went ahead on home, but when I hooked it up at home the computer went to the Msi best quality & performance screen, this went on for about 5 minutes. Then it brought me to a black screen with an underscore about 3 returns down and 2 spaces over. Does anyone understand whats going on or a way to help me? I'd love to play my computer sometime today =(