With Windows 7's release looming on the horizon, Microsoft is busier than ever paving the way for it to arrive. Part of that is cleaning up loose ends with beta testers, hoping to get them spring for a license or at the very least upgrade to an RC release. For those who haven't bothered to update from the beta, Microsoft will be "encouraging" them through forced expiration of their copies.

Starting today, anyone still making use of Windows 7 Beta will find their operating system shutting down every two hours. Having such a "kill switch" built into the OS likely will cause privacy advocate and others to voice concerns, but for a beta release of Windows it is certainly an understandable move.

Windows already has a tough rep to beat in terms of security, with a lack of prompt updates being one of the most common causes of a compromised Windows machine. Microsoft clearly doesn't want old copies of a pre-release Windows 7 on the Internet. If you still happen to be using the beta, there's no better time than now to upgrade to the RC, which will remain active for another year.