Cubase Pro 8 won't start

currently having the same problem. it seems Steinberg should offer more info on upgrading to Cubase pro 8. 7.5 works flawlessly on my system. I upgraded to version 8 $100.00 mind you for its most loyal customers. and I get this message that says. DWM COMPOSITION IS NOT RUNNING. PLEASE SWITCH TO AN AREO THEME WHICH I DID AND STILL GET THE ERROR MESSAGE. I have direct x 11 but can not figure out the WDDM 1.1 version or how to get it.I am using a Radeon 7000 series video card using 2 monitors…
I hate having to buy a new video card just to use the pro 8 upgrade. somebody please, is there a work around this???