Keep your old version of Windows updated for free with Windows Update Restored
Not everyone is running Windows 11 on their PC -- there are many who are not even running Windows 10. If you are one of a surprisingly large number of people still rocking an old version of Windows, you will be well aware that Windows Update no longer works.
The Windows Update Restored project can help though. This is an unofficial, community-led operation that makes it possible for Windows 95, NT 4.0, 98, Me, 2000 and XP users "to obtain updates like they used to".