Hi William, thanks for your feedback. In fact I have reinstalled everything from scratch and replaced the OS with a Windows 7 professional license I had. All works now! So I believe your diagnose is correct, there is an incompatibility between Scheduler and Windows 7 ultimate unless something is modified or set in the OS. I am happy to have solved the issue using the professional version of Win7, I hope this experience will help other users that may have the same issue, even if I believe many nowaday are opting to use Windows 10 (which has its own issues as well..).
Denny, you may want to keep this in mind in case anybody else may have similar troubles, Windows 7 Ultimate is not the right choice to install Scheduler unless you want to investigate deeper on a dedicated solution !
Clear skies