Have installed Parallels on 5 Macs this week. 3 installs were with Windows 7, and 2 were with Windows XP Pro SP3. Both of the XP SP3 builds throw a memory error in Explorer.exe when they attempt to shut down or restart, and never fully shut down until I do a force close. Both only really started doing this after the final patches were installed from the MS Update servers. It is consistent with both computers, every shut down and restart now. The instruction at "0x66904200" referenced memory at "0x000000000". The memory could not be "written". Any ideas from anyone?