Perhaps during all of that tweaking you are doing to your computer, you accidentally disable the sound control icon on the bottom right of your screen. You can return it to its rightful place on your taskbar with a quick settings change. Here’s what to do:

1.) Go to “Start–>Control Panel–>Sounds and Audio Devices.”
2.) Under the “Volume” tab, select “Place Volume Icon in the Taskbar.”

After this, you should see a little speaker icon on the bottom right taskbar on your screen. Good luck!