Hi i was woundering if anyone could help me. I've been searching the last few days to an awnser to my problem. I've just shelled out for a new mobo and graphics card, the problem is, on vista, when i try to load both graphics cards (to have 2 monitors, dual display) it says that one has been disabled because of error. I belive this is because my new graphics card has a WDDM driver? If the cards are from different manufactors they must have the same WDDM or i must force instal a XPDM I have a Matrox G450 card My new card is a ATI Radeon 2400 Pro - I belive this is the one causeing the problem, because it is a new card it uses the WDDM driver. I was woundering does anyone know a fix or a way i can force the ATI card to use XPDM? I havent found a way myself. My Stuff.. incase you need to know... MoBo: Asrock ALiveDual eSATA2 Graphics cards: Matrox 450, ATI Radeon 2400 Pro CPU: AMD64 X2 6000+ Thanks alot guys. James.