The upgrade from PD 3 to 4 went off without a hitch on my Mac iMac Core 2 Duo running OS 10.5.5. After the upgrade, it was immediate apparent with Win XP apps that their start-up and shut-down times were noticeably slower than they had been with PD 3. I ran Parallels Compressor and Advanced SystemCare just to clean up any loose ends, but that didn't make any difference. Is anyone else having this problem and, more importantly, figured out what's happening and how to cure it?
http://kb.parallels.com/en/5859 Please note, using Compressor, you are freeing disk space but slowing VM, as all files are started to use NTFS compression