This doesn't seem very user friendly (from the RC download site):
Watch the calendar. The RC will expire on June 1, 2010. Starting on March 1, 2010, your PC will begin shutting down every two hours. Windows will notify you two weeks before the bi-hourly shutdowns start. To avoid interruption, youll need to install a non-expired version of Windows before March 1, 2010. Youll also need to install the programs and data that you want to use.
Watch the calendar. The RC will expire on June 1, 2010. Starting on March 1, 2010, your PC will begin shutting down every two hours. Windows will notify you two weeks before the bi-hourly shutdowns start. To avoid interruption, youll need to install a non-expired version of Windows before March 1, 2010. Youll also need to install the programs and data that you want to use.