Let me add that Vista RC1 installed and works fine as well on my Mac Pro 2.66 w/4GB of RAM with this build (full ram enabled on Mac, 1500 on Parallels) with some caveats: 1) I occasionally get a VM crash that asks me to email Parallels when I start the Vista VM 2) A few times before I had the chance to install VM Tools, my Networking on my -Mac- stopped working. I had to reboot a couple of times to get it back. Console shows it being deactivated in the boot process, but seemingly before any Parallels driver even loads. I didn't have this problem running XP so it must have been some kind of fluke. All is well now. Vista support seems a bit wonky compared to XP support... and I can't figure out what disabled my Mac networking to cause me to reboot, but all is well again.