First, please read this post and give us a lot more information about your computer, the exact version of MEP you have and also exactly what it is you are trying to record from the Internet, especially if you are wanting to use MEP for this.
Briefly, if you are running Windows 10, under pressure from Record Companies Microsoft was forced to remove from Windows the facility that was present in earlier versions to record "What U Hear". There are ways to circumvent this but it is not easy!