On the contrary, I'm fairly sure many Flash games do not offer a volume control, and many people use the OS volume control to control the Windows dings as well.

I managed to find a work around though.  Seems I can adjust different channel balances - since I have 2.0 speakers, I just lowered the balance to the front speakers.
Still not as good as XP, and still can't adjust SW Synth volume (hopes all my MIDI apps have a volume control - don't recall Sibelius having one), but I'll see how it goes.