Maletone :
"Installed" as in plugged in to the computer or using it? what graphics card are you using? i3 is quite outdated...
I don't think you've even read his question properly. He already has the card installed and i3 isn't that outdated. Graphics card don't discrimate as long as PCI-e 16 slot is operational, the mobo should automatically detect the new hardware.
In your case I would suggest looking into your bios. Some bioses needs to manually switch your display adapater. Look for something called "Display adapter" and its set to "PCI-e" in peripheral section of the bios.
If your bios is PCI-e then windows is not detecting your hardware. The fix for this is to use your onboard VGA and manually go into windows hardware and device and display properties to check and detect. Also check your drivers, more than often the drivers are the culprit in hardware detection issue.