Always verify the SHA256 hash of any ISO you download to ensure it hasn't been altered from the original Microsoft version. Download Windows 10 Disc Image (ISO File) - Microsoft
Downloading this specific modified ISO ("San Lex") is due to significant security risks and its outdated status. Security and Legitimacy Report Always verify the SHA256 hash of any ISO
If you need a clean or specific version of Windows, always use official Microsoft sources: If you must have 21H2 for compatibility, tools
Download the latest, secure version of Windows 11 directly from the Microsoft Download Center . Safe Alternatives
If you must have 21H2 for compatibility, tools like Rufus can sometimes fetch older official versions directly from Microsoft's servers, which is safer than using a modified "San Lex" file.
Build 22000.978 is an old revision. Official current builds have progressed much further (e.g., Build 22000.3260 as of late 2024). Safe Alternatives