Starting January 14, 2020, Microsoft will no longer provide security updates, software updates and technical support for computers running Windows 7. Start upgrading the Windows 7 computers in your organizations or in your homes to Windows 10 ASAP.

This website, Windows 7 End of Life provides a nice countdown along with a calculator to determine how many computers you will need to upgrade per month, per week, or per day given the number of Windows 7 computers you have left to upgrade.

Nash Pherson, the creator of the Win 7 End of Life website also provides a nice PowerShell script to find all the Windows 7 computer objects remaining in your Active Directory. Great resource, Thanks Nash!

This is the Windows Lifecycle Fact Sheet for every Windows product available, which provides information for support timelines and more.