Of there is a way to do it by editing the registry, but Tweak UI will do that (and more) in seconds.
Thanks Floydoid, I had also seen that earlier, but do not like editing registry files "IF" I can help it.
Re: TweakUI
I tried the "Drives" setting in TweakUI but it did not work.
(All the drives were already selected, I even tried de-selecting and re-booting the PC then re-selecting, but it still did not work)
So I then tried the "Types" option which is just below the Drives option by checking the "Enable Autoplay for CD and DVD drives" and that worked OK.
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Sorry Exo but I never got around to trying your suggestion as TweakUI managed to resolve the problem, but thanks all the same.
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Text above edited.
Hope this may also help anyone else with the same or similar problem.