OK - I tried what you said. For
HKCU\ControlPanel\Sounds\RingTone0, I wiped everything except
<parm name="
Sound" datatype="
string" value="
\Windows\Rings\Ring-Birds2.wav" />
I also followed everything you had for
HKCU\ControlPanel\SoundCategories\Ring
I ended up with no volume on the ringer at all. I then went in and pasted back in all the keys for what you had for
HKCU\ControlPanel\Sounds\RingTone0 (all the keys you show above).
Now I have full volume. I now also have ringer volume control after I adjust a call volume control. Not sure why it is working as these were the original registry values I had ....
All works - curious how though ....