Re-enable the on-board video and uninstall all video drivers and clean the registry. power off disconnect the power from the wall or just pull out the power chord. Hit the start button a few time to blow off any residual capacitor storage. Reboot into the bios and disable the on-board video and make sure that AGP is set to 4x (do it manually). Save the bios and reboot...Now if you have problems, you may have "toasted" that GPU when you did the install, particularly if the powe rsupply was still "on-line" when you installed the card.
Noli Nothis Permittere Te Terere!!
EVGA 680i, Dual EVGA 8800GT'S (650/950), 4 gigs OCZ DDR2 1066, Intel Q9450 at 3.8 Ghz, Koolance Water Cooled, Dual Plextor16x DL DVD+/-RW. Dual WD 250gb 16mb Cache Sata 3.0. 3DMark06 score = 19,168.