Microsoft provides tools to download the latest available version of Windows 10, which often includes or supersedes the 2021 updates. How to Download Windows 10 For Free (Official)
Downloading a for the December 2021 update (technically version 21H2, released in November 2021) is best done through official Microsoft channels to ensure your system remains secure and stable. While the software is free to download, it requires a valid license (product key) for full, legal use. Official Download Methods Free Windows 10 Pro December 2021 Download