why don't you go back to the shop and change the card to a agp slot card . Im sure there won't be any probs with them changing it if u explane.
If you keep the pci card all you have to do is go into device manager and delete the drivers for the agp card the turn off pc put new card in and reboot. it should find new card and may ask for drivers and software on the disk you got with it
hope that was of some help to you
