I had no problems running everything under Parallels 6. I upgraded to Parallels 7. When I try to start Media Center, it gives me a low bit rate message and freezes Windows 7. I have to go into Mac's Activity Monitor and manually shut down Parallels. This occurs in Coherence mode. It usually takes two or more manual shutdowns to regain control. Sometimes, the entire Mac needs to be restarted. Activity monitor shows Parallels not responding. My system is a 27"iMac Core i7 with 16gig RAM, 4GB allocated to Windows as recommended by Parallels.