Microsoft SyncToy 2.1 – download

SyncToySetupPackage_v21_x64 – Download here

or from Microsoft official website – https://www.microsoft.com/en-us/download/details.aspx?id=15155

Windows 10

You need to enable the .NET Framework 3.5 (include .NET 2.0 and 3.0) features

features

Then run the synctoy setup