Thanks Mirek for your support and interest in the problem I face to.
I guess I have to track the version dll difference between the correct machines and the failling ones.
I try to know if some dlls were modified by the installation of RealVNC (previously lnown as WinVNC) from the web but I found nothing really interesting.
Perhaps I can move all the dlls of the System32 directory from a correct machine to a failing one. Of course I will make a save of the configuration before proceedding the operation.
What do you think about this ?
Regards
Biobytes
Well, me, I would installed U++ on failing machine a started debugging.
Maybe you can just compare System32 content first?