I just got my prompt on my PC. Windows 10 will retire on October 14, 2025 when Microsoft will no longer release security updates or technical support. As a result, users will need to upgrade to Windows 11 if the computer is eligible; the upgrade to Windows 11 is usually free. As for myself, my specific machine is incompatible with Windows 11 so I will need to replace this computer - which was purchased in December 2019.
Windows 10 computers will continue to function after the OS retires although without those future security updates. Yet again Microsoft announced the Windows 10 ESU (Extended Security Updates) program which is a paid service supposed to extend their support service so that it can still function in a secure manner. The price for ESU has not been announced yet and will be revealed closer to October 2025. Windows 10 was released in July 29, 2015.
On a segway, Microsoft ended their support to Windows 8.1 in January 2023.