Movie on Windows Movie Maker

I have a Samsung Camcorder, and then I uploaded the files to the computer. At first even Windows Media Player did not play, but after downloading the Codec it worked. When I transfer those files to WMM they just play as an audio file. What is hapening? What can I do ?

I did some testing, and I found that using the older (2005) version of the SEDG/SMP4 codec, Windows Movie Maker doesn’t display SEDG/SMP4 movies in my system either. I re-tested with the 2007 release and it works.
You can download the 2007 version here.
And thanks for the heads up. I updated our SEDG/SMP4 page.