If you're using Encoder 4 SDK (or appliable with previous versions) ,its possible you faced this problem:
It says the "Microsoft.Expression.Encoder.Utilities.dll" cannot be loaded in the project for encoding purposes.
Lets have a look at Encoder 4 Pro if its a problem regarding SDK or a missing .dll file.
Telling us it causes because of Desktop Experience not properly installed on our machine.
Since i use Windows 7 Ultimate,i know lots of features are already comes integrated except one: Windows Media Player
Have a look at what features are there in Desktop Experience
So we need to install Windows Media Player? After a little Bing search,i found it.Here you can download it here
Later i created a new project in C# used Encore SDK .dlls and everything worked like a charm.
This problem occurs lack of Windows Media Features.
Hope this article helps you and solved your problem.
Have a nice day!