Moved this from the 'other questions' forum since most traffic is here in the Windows Guest OS Discussion so maybe chances for a solution are better: Normal behavior when changing windowed to full screen is that the complete host desktop turns around and on the backside it's full screen. Now, with OS X 10.7 and Parallels' latest build, the screen suddenly turns black and the animation's second half flips as usual - on the back of this black screen is the full screened VM. Back to windowed mode is the same: Screen turns black, the black screen turns around and on the back is the host desktop with the VM's window on it. Since the 'getting black' is not a smooth animation but a sudden 'lights out' I suspect that this is not the intended behavior Any ideas?