I just wanted to share my experience. On my Windows 10 System I was getting the volume bar just like the picture posted by DavidHK129 automatically keep going all the way up to 100% and then stuck on the screen. I use Microsoft SideWinder X6 Multimedia Keyboard. So every time I rotate the volume knob on the keyboard, the on screen volume bar would operate properly (up or down) but as soon as I let the knob go, the bar would go all the way back up to 100% and stayed there. I tried many things, tweaked many settings, even uninstalled sound card driver, keyboard driver everything and then re-installed. I even did a system restored but the problem came back.
Well, last week I noticed for the first time that instead of going all the way up, it is going all the way down to 0% and volume bar staying on the screen. So I started thinking differently. Instead of "vol bar get stuck on screen" I started to think "vol bar staying activated", which raised the question, "why?" I imagined the answer would be, either the keyboard volume knob is continuing to send a up or down signal to the PC and PC is responding by raising or lowering the volume all the way up or down, and since the keyboard is continuing to send the signal, the on screen bar is remaining activated.
So the source of my problem boiled down to the keyboard, either a hardware (as in a short circuit either to the highest point of vol or lowest), or a firmware (I do not know exactly how this keyboard operates but I assumed this kind of short is possible to be created by the soft error as well as hardware). My keyboard connects to the PC via USB. I made a two-step plan.
Plan A: To disconnect it from that USB port so it can clear out any soft error with that particular port, and then to reconnect to another USB port. If that will not solve the issue, then
Plan B: To take apart the keyboard and find any hardware issue, that is causing the volume control to be shorted on either up or down point. It may be as complex as changing the variable resistor (if not something else) or may be as simple as dirt accumulation (yes, it is a old keyboard), or even be a stuck piece of paper or a broken staple from my table.
Yesterday I executed plan A. I removed the keyboard off the USB from the running system. The stuck up volume bar disappeared right away. I plugged it back in to the same USB port. After a few seconds the vol bar came back up with same symptom which is keep sliding all the way down to 0%. I took it off again. It disappeared. I plugged it back into another USB port. No problem. I played some music. I operated the keyboard volume control up and down. It operated like it should. The volume bar showed on screen while I operate, and as soon as I let it go, the bar disappeared. I raised and lowered the volume using the mouse. It operated perfectly without sliding up or down by itself. It's the second day I haven't seen that problem anymore. Now I felt like sharing my experience with everyone else out there who are having the same issue. Everyone's problem might not be the same, but it might help someone.
Cheers!
