No Sound on Windows when Using Windows' Built-in Bluetooth (No Adapter)

This Troubleshooting is for Connecting a Bluetooth device DIRECTLY to your Windows Computer's Built-in Bluetooth.
The Built-in Bluetooth of some old PCs might not work, or not work well, thus, you may not be able to use the direct Bluetooth connection, or have unstable connection, hear choppy sound cutting out intermittently, etc., in this case, please try the following solutions: 

Solution 1.  Reboot your Bluetooth Driver
  1) Right-click the Start button, select Device Manager.
  2) Find “Bluetooth” section,  then Right-click on your device Bluetooth driver and select  “Disable device”.
  3) Restart your PC and repeat the above steps to Enable the Bluetooth driver again   (select  “Enable device”)
  4) Pair your Bluetooth Headphone/Speaker/Receiver with the PC again.


Solution 2. Use an External Bluetooth Driver
This method essentially "Bypasses" your Windows' built-in Bluetooth.