I have been watching this forum all week and been very hesitant to install version 4. tonight though I took the plunge with build 3540 I have a MacBook Black 4gb latest OSX version. I did do a few things first so these may make it easier for you. I opened windows VM and disabled the virus and internet security software plus the auto updater from windows, turned off the firewall (in windows not MAC) and closed windows fully using shutdown. I did a manual backup of the library folder where parallels was stored (including vm files) and copied the dmg from 3.x as a backup to external disk. I accepted the backup in the installer to external disk. I removed the external disk I ran the installer At the end of each stage it starts windows and this wanted to be activated, i declined each time, it then opened a box for new hardware found, I ignored it and after a few seconds the next stage began. This i did for each of the 3 remaining stages. At the end it rebooted after installing parallels tools and once again asked for activation, I again declined. It found new vga and pci then started normally Once started i opened IE to force the proxy to find its way to internet then used programs-system tools- activate to reactivate windows. Went back in and turned on Auto Update, firewall and virus software I now have version 4 running fine, nothing missing, network working all as I expected. Hope this helps someone..... Now off to try it on a MacBook Pro... Neil