Hello, my name is Emmanuel, and I am an independent advisor. I'll be more than happy to assist you today!
I am so sorry to hear that you are having an issue unmuting your laptop computer. So just to clarify, you put the built-in speaker in your laptop on mute but were unable to unmute it? Have you tried right-clicking the sound/speaker icon on the taskbar, selecting Open Volume Mixer and then under System, increasing the volume slider? You may also try going to the search bar on the taskbar, typing in and searching for Device Manager, then clicking open. In the Device Manger window, double-click "Audio inputs and outputs" > right-click on your computer's external speaker, then select update driver > search automatically for drivers. If this didn't fix the issue, you may try selecting uninstall device, restarting your computer, then muting and unmuting your external speaker again.
I hope this information can help you.
Let me know if this fixes the issue.
I look forward to your reply.