No listening sockets available

Each socket is allowed to be used only once, but my computer is a problem that cannot bind to port 80, what's going on.
Tip Error is:
Make_sock:could not bind to address 0.0.0.0:80
No listening sockets available,shutting down
Unable to open logs

Workaround:
This problem occurs because Apache's default port is occupied. The workaround is to remove the port occupied by this port. Or switch to Apache's footprint port.
The Apache port is a good solution. Just change the configuration file. Now let's talk about how to change other files to occupy the workaround of the Apache default port 80.
First, see which program is using the port. Method is: Netstat-a-O you will currently be listening to the port program and the corresponding port and program PID, remember to occupy this port this program PID, the general long port such as 80 will be displayed as http,21 for FTP, so, All you have to do is remember the PID of the corresponding program.
Then, use Task Manager to find the PID that belongs to this program. Kill this process and then start Apache. It's done!
As for Linux, other non-Windows systems look for process PID and kill methods. Take a good look at the corresponding command. It's very simple. Oh, it's over.