What method are you using to get the movies to the computer (firewire, USB,
DVD, etc.) If this is a true DVD burning camera of which I couldn't find any
on JVCs web site, you will need software provided by JVC to get the video
into a format that WMM can use.
If this is one of their Hard Drive cameras, this produces a file as an MPEG2
format that WMM can't use directly and you need to covert it with a
conversion program. Search for MPEG2 to AVI conversion in Google.