Windows 8.1 Support Lifecycle Policy
The lifecycle of Windows 8.1 will remain under the same lifecycle policy as Windows 8 with support ending 1/10/2023.
Windows 8 customers will have two years to move to Windows 8.1 after the General Availability of the Windows 8.1 update to continue to remain supported under the Windows 8 lifecycle.
Visit the Support Lifecycle site or contact your Microsoft Support Professional for answers to additional questions you may have.
With the General Availability of Windows 8.1, customers on Windows 8 have 2 years, until January 12, 2016, to move to Windows 8.1 in order to remain supported.