NONE of the above things I tired corrected the stutter problem.

turned on/off a variety of features within the graphics card control panel-and tested each change. swapped out the HDMI cable from the comp to the monitor to a DV-D cable

turned on/off a vareity of features within power dvd -and tested each change rolled back my graphics drivers (I have a GeForce GTX980 card on the desktop I was doing all this with)

re-installed the basic build of the program, then incrementally installed each update-and testing a video at each point I've tried every 'fix/suggestion' I can find-NOTHING has yet made a difference. So it's very very unlikely it's an OS or comp manufac. I also should state that I purchased 3 PowerDVD 15 Ultras-2 desktops and a laptop (all running different OSes, vid cards and from different computer manufacturers). It's not the encoding of the above video files that's the issue, as they all play 100% smoothly on other players I have-like jRiver Media Center 21, Zoom Player Max, VLC. I still get a slight 'stutter' when watching most video files (i.e. I try some 'fix' and it 'seems' to work, but then. I've been battling this same problem for quite a while.

Powerdvd 15 ultra