Yes, per Huff's comment, it has nothing to do with 100% vs. 125%. If you boot the system and the volume icon does not appear, then logout and login again, it will now appear.
Very weird. I had a similar problem with the power icon and fixed that - see http://www.technipages.com/windows-system-icons-missing-from-notification-area/comment-page-1#comment-764317
But that solution did not work for volume and this one is a "band-aid". Still looking for a real solution.
Thanks for all the ideas though. This was a good try.
Oddly enough no one in MS applications/programming is chiming in to resolve this issue, why? 40 thousand opinions and not one single solution. A physical count on googling issue produces over 70% of the systems that have installed 10 have this issue. A simple
Registry hack (which I will not share worked for a single session), but adjusting font size? Really? The problem is a technical issue in the design software, not a wysiwyg fix um up. MS fix your broken toy! Once again another "consumer beta test" to reduce
your cost at our expense. Going back to Linux maybe the best option MS just keeps failing at every turn. Go look at the **** that is broken and the overhead it takes to run this junk for a pretty color filled screen, productivity zero to 5% maybe.