If your apache server display some errors related to port such as Port 80 in use by “system”!.
This problem you can solve changing configuration of apache.
You need to set the port number in httd.conf configuration file of apache server.
Path : \apache\conf\httpd.conf
Then change the line
Now restart your apache server.
If you want to check which program is occupying the port
NETSTAT -p tcp -ano