Every Windows version has a .NET Framework version installed and enabled by default. In Windows 11/10, .NET Framework 3.5 is disabled by default. But many programs still require .NET 3.5 to run.

Additionally, if you don't want to download the whole Redistributable package from Microsoft (thus skipping steps 1-3), download only the CAB file for .NET Compact Framework 3.5 from MoDaCo.

Developer ‘confusion’ over the download size of the .NET 3.5 framework service pack one has led to the creation of a free online tool and new client profile configuration option.<br/> ...

Microsoft has warned Windows 11 users that they might experience issues launching and using some .NET Framework 3.5 applications.