How to maintain video quality in Movie Maker

I have a video that has the following;
-Length: 528
-Frame Width: 208
-Data Rate: 844
-Total Bitrate: 974
-Frame Rate: 25frames/second


I'd like to keep the quality because it's actually pretty good but every time I save it 'as a movie' in Movie Maker the quality changes dramatically.

Can someone please help me sort this out.
thanks