First thing you always want to make sure you do is to unistall the last video card,exp: goto add remove programs with original card in, remove the drivers. then reboot and let it install as a standard display adapter, then shut down and remove old card and install new card, (read quick setup guide to make sure you follow instrutions) and load new drivers, if this doesnt work or if the old card doesnt work anymore post back will try to help more with different ideas