How to stop the beep tone when the wrong keyboard button is pressed?

I can recommend you to "Mute" speaker for your system to avoid such noise from wrong pressing key. You can do it via small icon on the desktop bar shown or through control panel at your system.

I have got the solution for this.
You need to follow below steps to disable the system beep sounds.

1. Right-click on 'My Computer' icon on desktop and Select 'Manage' (Computer Management screen will open)
2. Select 'Device Manager' from left panel list.
3. Go to 'View' menu and select 'show hidden devices'.
4. You will get the name 'Non-Plug and Play Drivers' in right panel list of Device Manager screen. Expand the list of 'Non-Plug and Play Drivers'.
5. Double-click on the name 'Beep' from the list of Non-Plug and Play Drivers'. (Beep Properties screen will open)
6. Select the button 'Stop' in current status field.
7. Choose the option disable from Start up Type field and select the option 'Disable'and click on 'Apply' and 'OK' button.
(You can select only name 'System' from list and stop the same.)

That's all, you will not get disturbed by the unnecessary beep sounds on your system even if your system speaker is ON.

Please follow the steps to stop the beeping:

1. Open the Device Manager from control panel.
3. Change View menu to show hidden devices.
4. Select the Non-Plug and Play Drivers.
5. Open the 'Beep' from the list and enter the Beep Properties.
6. click on Stop button in current window.
7. Click the disable option from Startup, and disable it
8. Click on 'Apply' and 'OK' .

Make sure you disconnect the Speaker from the system or select the mute option.

You have to use Device Manager option from the control panel in your system. Just open the Device manager via Control panel -> Device manager. From there select view menu to see hidden devices. Now select the properties of 'Non plug and Play drive s' and select the button stop under beep properties. Now restart your computer. That is all!