Open the original WMV file in Windows Media Player and see if you are able to seek to any random position. If not, then the WMV file is not indexed and hence cannot be edited.
To fix this problem, we have to make the file seekable. You can add the WMV file to the timeline and without editing it further make a movie to a temporary AVI file. Use this AVI file for all further editing.
You can also try using the Digital Media Converter which has a media file repair utility. You can download Digital Media Converter from the following link:
http://www.deskshare.com/download_details.aspx?ID=18You may also find our user guide section useful:
http://www.deskshare.com/vem-help/TroubleMakingMovie.aspx
DeskShare - Support
