I am directing this to any techie at Microsoft.

My video camera saves the video as motion JPEG (avi) files.  I previously used Movie Maker 2011 on another PC running Windows 7 and it edited my video files very well.  I made many videos with lots of editing, including special effects, with no problems.

Now I have a new PC running Windows 8.1 and Movie Maker 2012.  This version of Movie Maker can import and play my video files and save them as WMV or MP4 videos.  But I can't do any editing.  I can't trim the video clips, or add special effects like transitions.  If I try to edit the clips, Movie Maker crashes. 

If I convert the motion JPEG files to XVID-AVI or to WMV, then Movie Maker works OK, but I'm concerned that the conversion will degrade the video quality.  I want Movie Maker 2012 to work with the motion JPEG files straight from my camera, just like Movie Maker 2011 did.

Installing a K-Lite codec pack did not help.

I tried installing Movie Maker 2011 on my Windows 8.1 PC but it would not run. 

How is it that Movie Maker 2011 on my older PC worked fine, but Movie Maker 2012 on my newer PC won't work?  What did Movie Maker 2011 have that is missing from Movie Maker 2012? 

PAPAJOHN: You already replied to me before, thanks.