But Microsoft does not maintain a single, public directory of every old ISO. Instead, the “index” must be compiled from official sources (Microsoft servers), community knowledge bases, and verification hashes.
If a server administrator does not configure a "home" page for a specific directory, the server generates a raw file list. This page usually starts with the header followed by a list of links.
Use these specific queries on Google, Bing, or DuckDuckGo: