You should put the httpd.conf file back to the default settings and anything else you changed so you at least know that this configuration file is now without any changes you may have made that will in future cause issues.
Ignore the port 80 status message in the XAMPP Control Panel as it is hard coded.
Do read the C:\xampp\apache\logs\error.log file and look for clues why Apache can't start at about the date and time you last tried to start it, usually because there is another server on port 80 that needs to be disabled like Skype, World Wide Publishing (IIS) or any number of apps that are now using port 80 by default - Apache can't share port 80.
To see what is using the ports that XAMPP requires exclusively, use this nice little freeware no-install app. CurrPorts from here:http://www.nirsoft.net/utils/cports.html