The countdown has run out on the first editions of Windows Vista to expire. May 31, 2007 is the last day for Windows Vista Beta 2, Release Candidate 1 and Release Candidate 2. "Back up important data from Windows now. The Windows license will expire in X days. Back up your files, and then install any edition of Windows Vista," is the cry that the dying test editions of Vista are sending out to customers.

Microsoft's beta 2 and RC1 and 2 versions of its latest operating system were offered for free to participants in the testing program but were also time-bombed for the end of May 2007. The Redmond Company has offered all testers the possibility to upgrade from Windows Vista Beta 2, RC1 and RC2 to the editions of Windows Vista of their preference.

After today, all the testing builds of Vista will deliver only two hours of limited functionality followed by reboots. However, while today signals the expiration of the beta, RC1 and RC2 build of Vista, the actual D-Day will be 28 August 2007, after which the operating systems will no longer boot at all.

Surprisingly enough, the $399 high-end edition of Windows Vista Ultimate will be the next to go, according to the official Microsoft Support Lifecycle information. Currently, Mainstream Support for both 32-bit and 64-bit versions of Vista Ultimate is scheduled to be retired on 4/10/2012. Microsoft does not, at this time, plan to deliver extended support for Vista Ultimate.

This means that Windows XP Service Pack 2, an operating system that will benefit from a five-year life extension announced in February 2007, will outlive Windows Vista Ultimate. Windows XP Home Edition and Media Center Edition will be supported through 2014. And, in this context, Windows Vista Home Premium, Windows Vista Home Basic N and Windows Vista Home Basic will also survive. Microsoft will deliver extended support only for Vista Business and Enterprise editions until 2017.