Microsoft Msxml 4.20.9818.0 ●

Note. Support for XML Core Services 4.0 has ended. Support was only available for Service Pack 3. Microsoft Learn

Older applications (like Toad for Oracle, SQL Server tools, or older games) install it as a necessary dependency. Microsoft Msxml 4.20.9818.0

You likely didn't install this manually. It usually arrives in one of two ways: SQL Server tools

This software is considered and a significant security risk. Microsoft Msxml 4.20.9818.0