Try removing the NIC card and rebooting without the NIC installed.
Remove any NIC drivers present in "Device Manager -> Network Adaptors" (although there shouldn't be any there)
Reboot again without the NIC installed to make sure the drivers are gone.
Shut down, install the NIC in PCI slot 4 (or maybe try slot 3 or 5), reboot, skip (cancel) the "New Hardware Found Wizard", manually install the drivers in Device Manager.