[en] List open ports on your PC

Have you ever wondered which ports are open on your PC? Both active outgoing and listening?
A tip is to use netstat which is built into Windows. I used the netstat -ano command (from the command prompt) to find a process which was using a port, which was meant to be used by another program. The above command will provide you with the Process ID (PID) of the program for each connection. The use the Windows Task Manager to find the PID (can be seen under the Processes tab, provided that you have selected the PID to be display).