Completely forgot AMD can do Crossfire without the actual connector. I feel dumb now lol
All he needs to do is power off the computer, plug in the second 5450 into an open PCIe slot, reboot the computer, and reinstall the latest drivers from AMD. Then it's a simple setup through Catalyst Control Center to enable Crossfire.
I think you still need the bridge or the old style dongle for x-fire to work the cards must be connected in some way other that just in the slots.. and being a store bought computer I don't think it will do to there bois may be ''locked'' and do not allow certain upgrades if any but theres some that do good luck