How to fix apache not starting in XAMPP/MAMP.

How to determine what software is using port 80 or any port.
1) First download and instal XAMPP then
2) Start the XAMPP Control Panel
3) Start the Apache and MySQL components. You can also start the other components, if you plan to use them.
4) Verify the Apache install, by clicking on the Apache administrative link in the Control Panel.
5)Verify the MySQL installation, by clicking on the MySQL administrative link in the XAMPP Control Panel.
If the verification steps are successful, XAMPP should be successfully installed on your PC. Open a browser and enter "localhost" on your address bar. You will be redirected to a page telling you that you've successfully installed xampp on your system ( towards the end of the video). and you don't need to go farther from here. If not or if you get an error on starting one of them like me, then follow the next steps
6) Sometimes changing the port number works but you'll not get success if you just edit the port number
7) If not lucky by editing the port number in note pad then you need to change the port number for the application that's using it or you need to stop the application. In this case
8) start/cmd/enter and run "netstat -ao" on windows 7 or -a, -n, -o ...else on others like xp, server...
9) Look for the PID of the application thats using port 80. Some OSs show you the name of the application but mine doesn't.
10) Go to Task manager enable the PID from "view" manu and look for that application with the PID number. In my case PID 4 was using port 80 but PID 4 is not showing in task manager.
11) You can now disable the application thats using the port you need from the task manager or if not like in my case, I was 50% sure it was HTTP but it didn't show up. if you're like me just follow the next steps.
12) start/RegEdit/Enter/HKEY-LOCAL MACHINE/system/CurrentControl set/Services/HTTP/right click on start and modify it. Change the value from 3 to 4 and reboot your computer. Restart XAMPP.