Microsoft Expression Enocoder 4 Screen Capture

So after testing a few useless screen capture softwares I downloaded microsoft expression encoder 4 screen capture. The problem is that it puts out massive screen capture video files. On a 15-20 sec screen capture it produces a 17.4MB file. And here is the confusing part when I choose a lower birate but same frame rate the video is choppy and unwatchable but I have to select 30000kbps opposed to...