Attention Windows 7 Beta and Release Candidate (RC) testers! To avoid interruption, you’ll need to start planning now to rebuild your test machines using a valid version of Windows before the software expires.

Windows will notify you that the expiration process is beginning and two weeks later your PC will begin shutting down every two hours.

The Beta expires on August 1, 2009, and bi-hourly shutdowns will begin July 1, 2009. The RC will expire June 1, 2010, and the bi-hourly shutdowns will begin on March 1, 2010. In both cases, you’ll need to rebuild your test PCs with another valid version of the OS, and reinstall your programs and data.

The Windows 7 RC is available now to TechNet and MSDN subscribers and on www.microsoft.com/springboard starting May 5th.