For anyone still using a Release Candidate (RC) build of Windows 7, it's worth remembering that, if you haven't upgraded by March 2010, your operating system will become an ex-operating system before too long.
Arstechnica has sent out a courteous reminder before Microsoft sends round the frighteners to shut your computer down.
From February 15, 2010, Windows 7 RC (build 7100) will kindly start telling users to purchase an upgrade if they want to continue enjoying the benefits of Windows 7.
If you haven't updated by March, then Microsoft will start shutting Windows 7 down every two hours, as you should remember from this foreboding Windows teamblog:
"For the RC, bi-hourly shutdowns will begin on March 1st, 2010. You will be alerted to install a released version of Windows and your PC will shut down automatically every 2 hours.
"On June 1st, 2010 if you are still on the Windows 7 RC your license for the Windows 7 RC will expire and the non-genuine experience is triggered where your wallpaper is removed and 'This copy of Windows is not genuine' will be displayed in the lower right corner above the taskbar."
The threat is palpable. If you want to keep using Windows 7, you can use the Windows 7 RTM (build 7600) instead.