<A target="_blank" href="http://www.pcworld.com/article/188281/running_windows_7_rc_prepare_for_shutdowns.html?tk=rss_main">For those still running the release candidate of Windows 7,</A> your systems will start shutting down soon. Beginning February 15 the operating system will start to nag you with expiration notices. By June 1, your system will start rebooting itself every couple of hours.