manic

Lets see if I got this right. You upgraded video card on your machine,
vista, no problem.
Then you installed the other new card on wifes machine, and you get
a error.
Then you took the same card and installed in your machine, and you
get a error? If that is the case I would suspect the card being bad.

If thats not the case and you installed the card in your machine and
it was ok, I would suspect a power supply issue with your wifes machine.
Maybe Im confused. A pci-e card needs at least 26amps on the 12volt
rail in order to work, then you need to take into account the age of the
psu, and the efficeincy of the said psu.