Problem:
Some antivirus applications delete the contents of the Temporary Files folder (%temp%) as part of a reboot. Setup programs, such as Team Foundation Server and Visual Studio, may require restarting your computer during installation to complete part of the installation. In many cases, state information is written to the temp folder to support the continuation of the installation after the computer restarts. When antivirus software is configured to delete items in the Temporary Files folder on reboot the setup program is unable to maintain state and therefore the installation process cannot continue.

Solution:
Disable your antivirus program during setup, or at least disable the feature to delete the contents of the Temporary Files folder. In addition, disabling your antivirus program may reduce the time necessary for setup to complete.

Applicability: Visual Studio 2005 Team Foundation Server, Beta 2