hello Jarw00,
and a welcome here, if you want to stay
with Window mediaplayer you might want to update and download
all available codecs.
You can also download an additional viewer called videolan,
http://www.free-codecs.com/VideoLAN_download.htm
This viewer has never let me down, and they post here a lot of
different files.
But first of all
click here
regards,
woudenstocks