If you want to enable .NET Framework 2.0 and .NET Framework 3.5 in Windows 11, then follow the steps mentioned in this article.

This web page contains information about the Add or Remove Programs control panel entry - Microsoft .NET Framework 2.0. More information can be found by visiting this search result.

The original framework” has proved useful everywhere from schools and small businesses to local and foreign governments,” NIST said in announcing the 2.0 version.