Had an issue today installing Trend WFBS 7 on a clients new SBS 2011 box. Updates were installed pending reboot so Trend was complaining about a reboot needing to be done before the install. After the reboot, still got the same error.
“The security server cannot be installed on this computer because the system has installed a Windows Update without having been rebooted. Please reboot the computer before proceeding”
Solution is to run the install as another admin user.