# Appendix G. Solving Ports Listening Problems

TCP/IP ports range from 1 to 65535. Abyss Web Server reports a listening problem on a port when one of the following situations is happening:

- Another instance of Abyss Web Server is already running on your computer.

- The port is already used by another application: Try stopping the other applications running on your computer to know which one is already using this port. More specifically, port 80 is usually used by other web servers. So if Abyss Web Server cannot listen to this port, there are chances that another web server is already running. Some Windows versions install by default Microsoft IIS (Internet Information Server) which uses port 80. If you do not use IIS, disable it or uninstall it to free this port.

An alternative solution would be to configure Abyss Web Server to use another web host or console port. For more information about changing the host port, refer to "Hosts Management".

If you have to change the console port, select Settings… in the main window, enter a new value in the Port field , press OK and confirm starting the server.