You can use netstat to see the process id of what is running on port 80 (or any other port for that matter). Here is the command you would use.
netstat -p tcp -ano
You can then start Task Manager and find the process that has that PID.
If you don't have a PID column you can add it.
- In Task Manager go to the Processes tab
- Go to the View menu | Select Columns... menu item.
- Select PID (Process Identifier)
- Click OK