From today, PC users still running the Windows 7 RC (release candidate) code will find Windows will shut down after two hours' use.
Microsoft said users' work will not be saved during the shutdown. Windows 7 RC will fully expire on 1 June 2010, and this is the first phase of its expiry.
When the OS shuts down, the Windows wallpaper will also change to a solid black background with a persistent message. Microsoft said, "Users will also get periodic notifications that Windows is not genuine. That means their PC may no longer be able to obtain optional updates or downloads requiring genuine Windows validation."
Users of Windows 7 RC have been advised to reinstall a prior version of Windows or move to Windows 7 RTM (release to manufacture) code. Microsoft said users will need to run a custom (clean) installation to replace the RC version of the operating system. "As with any clean installation, you will need to back up your data, then reinstall your applications and restore the data," it advised.