Originally Posted by MindoverMaster
Does that card need a PCI-E 6-pin power cord?
^This. If the card requires auxillary power which you haven't connected then that's likely the cause of the failed boot. Also as above cleaning the card and ensuring it's seated properly is worthwhile. Failing those then test the card in another machine if possible (had it only recently been removed from your friend's pc and was working then?). Again as mentioned above the power supply is potentially a problem too...Not entirely sure why I'm posting when it's mostly been covered