Microsoft has confirmed that users can no longer use old Windows 7, 8 ... Windows 11 is still a free upgrade from Windows 10, license keys for the latter can still activate Windows 11.
The installation path to obtain the Windows 7 / 8 free upgrade is now removed as well. Upgrades to Windows 11 from Windows 10 are still free. Although old Windows 7 and 8 keys can still activate ...