A: None. Only domains owned by Microsoft: microsoft.com , microsoftstores.com , download.microsoft.com , or software.download.prss.microsoft.com .
The 21H2 update was a "Cumulative Update" style feature enablement package. It did not introduce a radical UI overhaul. Key features included: win1021h2englishx64iso microsoft
Click the three dots (menu) -> -> Network conditions . A: None
Direct public download links for specific older ISOs like 21H2 are typically removed from the main Microsoft Software Download page win1021h2englishx64iso microsoft