Windows lifecycle fact sheet

Windows lifecycle fact sheet Last updated: October 2013
End of support, end of sales, service packs and updates. Windows downgrade rights,
every Windows product has a lifecycle.
The lifecycle begins when a product is released and ends when it’s no longer supported or sold.
Knowing key dates in this lifecycle helps you make informed decisions about when to upgrade or make other changes to your software. Here are the rights and limits of the Windows lifecycle.

via Windows lifecycle fact sheet – Microsoft Windows Help.