I'm attempting to open and play a movie (WMV format) in Movie Maker.  When I import it and press play, I get a brief scratchy sound, and then nothing.  Sound also stops working on other applications (e.g. Chrome, which was playing a YouTube video).  When I closed Movie Maker and restarted other applications, sound was restored.  This happens every time I attempt to edit a video.  I'm running Windows 8.1 with the most recent version of Windows Essentials.  Any thought on what could be causing this?