What’s Using Port 80?In Windows - open a command prompt:

Enter the following on the command line:netstat -aoThe active TCP addresses and ports will be listed — locate the line with local address “0.0.0.0:80” and note the PID value.Now right-click the task bar and select Start Task Manager. Navigate to the Processes tab and, if necessary, click View > Select Columns… to ensure “PID (Process Identifier)” is checked. You can now locate the PID you noted above. The description and properties should help you determine which application is using the port.The Task Manager allows you to kill the process, but be a little wary about doing that — especially if it’s “NT Kernel & System”.