New
#11
To answer your question, .NET 4.0 is suppose to be backward compatible with the other .NET versions. However if the program (MPEG4 Modifier) is calling for a different version it will not use 4.0.
So check the Features and see if Windows .NET Framework 3.5.1 is either shaded (windows default) or checked to active the other versions.
See my post#5
Jim