Time is running out! All Pre-Release versions of Windows Vista are set to expire on May 31, 2007. This includes the Beta 2, RC1, and RC2 versions that were part of the Customer Preview Program (CPP).
What happens if you don't upgrade the pre-release version? After May 31, 2007, after 2-hour sessions, the PC will automatically reboot without providing the opportunity to save data. Even the ability to log in normally for 2-hour sessions will only be available for a limited time.
Upgrade information is available at the Windows Vista Preview pages. See the Windows Vista Blog for additional information.