It's hard for me to figure out which app is using port 80 when I need to run up web server in windows before.

But now I realize how to find it out.

Use this following command to get process id of the application which is using port 80.

p.s. Ofcuz you can change to any port number you want.

netstat -nao | find "0.0.0.0:80"

Then put the process id into the column named 'process_id' below, we'll have a vision like the following picture.

tasklist /fi "pid eq [process_id]"

Here I use 'httpd.exe' to be the sample, at the first time I solve my problem that is skype dibs port 80.

Hope these help. :P