i don't see how the computer isn't powerfull enough to power the new card. do you mean the card fails to start as a result of the psu not being powerfull enough? or is the card too new for the type of board (i.e. card maybe 16x pci-e while board maybe supports up to 8x)? or is it simply that the psu doesn't have enough leads to power the graphics card? if its the latter then borrow a lead from the drive (assuming it is the same connection) and use that to see if it gets to the bios without the zeros. it obviously won't boot however you can tell within seconds if it is the cause - then you can think about getting power to the card, well at least that's how i would go about it.