I have had this problem on and off for over a year. It was not only that the volume was stuck at 100% but it also disabled the touch pad so I could not move the pointer or even use the pad to turn the computer Off or to Sleep. I always had to use the mouse
or hold the Off button on the side of the computer. The other issue with this problem is that in the software I was using (Sketchup) every time I would hit any key on the keyboard then a large volume icon would appear in the middle of the screen, stay there
for a few seconds, then fade away until I hit another key then it would do it again.
Solution??? One thing I noticed recently is that I had tried to use the "Music" app that comes bundled with Windows 8. This is the one that opens X-Box. Being that this was the only thing that I could recall I had done
differently before this last bout with the volume button sticking I did an uninstall of that app.(I right clicked on it and clicked "Uninstall"). As soon as the app was uninstalled the volume icon in the upper left corner went away, the large
volume icon no longer appeared in the middle of the screen, and the touch pad now works as it should. Because this has been an on again off again problem I will not be sure if this is that long term solution but it sure feels good to get back down to business
again. WOW. This has been a major, major issue!
Proposed as answer by
Tuesday, April 14, 2015 11:42 AM