We are running an SBS2008 for several months now. Yesterday i've installed SP2 using windows update and rebooted thed server. When the server was restarted and i tried to log in again, it kept saying: stage 3 of 3 installing sp2 64% completed. After an hour I was sick of waiting so i issued a 'shutdown /r /f /m \\computer /t 00' command from another server. Nothing happend. I then tried to reboot the server with LogMeIn. This worked and i was able to log in again. I immediatly received an error message saying that there has been an unauthorized change and that i need to reinstall windows to activate. I checked the history of windows update and the installation of SP2 was successfully. I then tried to manually reactivate windows but I got another message saying that i need to reinstall windows to activate. Insert the windows installation cd.