Quicktime on PC stuttering during Video displays

[Francis Nugent Dixon]

Hi from Beautiful Brittany,

Running LiveCode 5.5 on my Macs for many years with several
very successful conversions to a PC platform (Windows 7)
Apart  from some field parameters and choice of "more PC"
oriented character sets, I could convert in no time. Happy Bunny ! 
However, some of my Apple Livecode stacks use Quicktime to play
my audio and video tracks. For MP3, Happy Bunny once more ! 
With .MP4 (et alia), I get glitches during replay.
I've seen warnings about Quicktime on PC but I ignored them as my
video use was very limited. I put the problem on the back-burner.

Recently I use much more video, and have to solve the problem.
Google searches invited me to use VLC or KMPlayer.

What modifications must I apply to choose a good solution ?
LiveCode Help on the internet is obtuse !
Does using the "dontuseQT" command solve this problem (sounds far
too easy, even for LiveCode ….. !)

I hope that  my LiveCode status of 5.5 (can't afford LiveCode updates)
is not going to restrict me in any way.

I have a feeling that Klaus could help me out here ! (thanks for the music)

Thanks for any help

-Francis