Note:  Computers equipped with a 9-pin serial port will generally regard that port as being "Com1".

...... however, if a serial-USB adaptor is connected to the computer, this adaptor will be assigned a different port number and this new port number must be entered into the configuration panels above.

This new port designation might typically be Com4, Com5, Com6, Com7, etc. depending on how basic or otherwise the computer is and depending on which USB port the adaptor has been plugged into.  

To find the correct port number:

1. Open Control Panel

2. Double-click Device Manager

3. Expand the Ports title

4. Note the port number that has been assigned to the adaptor/ converter.

5. Change the input port number in Abel's Options/External Bells panel.

6. Save these changes ..... simply close Abel and then click "yes" when asked if you want to save the changes you've just made.

7. Re-open Abel and you should find all is working.