localhost not found

[nrabus]

Hello. This is my first post and just joined this forum.

I am using XAMPP for my Computer Info Systems course. I don't have time to wade through the forums to find the answer (I'm sure someone has had this issue). I will search instead of just opening a new topic thread from now on.

I used the control panel to start Apache and MySQL, getting "Status change detected: running" for each. My course instructions say enter http://localhost/ in a browser to check connectivity, but I get

HTTP Error 404. The requested resource is not found. The xampp control panel shows both running. I changed the port number for each in the config section AND the config text file.Test of my control panel log shows:
9:05:38 PM [mysql] Attempting to start MySQL app...
9:05:38 PM [mysql] Status change detected: running
9:05:49 PM [Apache] Problem detected!
9:05:49 PM [Apache] Port 80 in use by "Unable to open process" with PID 4!
9:05:49 PM [Apache] Apache WILL NOT start without the configured ports free!
9:05:49 PM [Apache] You need to uninstall/disable/reconfigure the blocking application
9:05:49 PM [Apache] or reconfigure Apache and the Control Panel to listen on a different port
9:05:49 PM [Apache] Attempting to start Apache app...
9:05:49 PM [Apache] Status change detected: running
9:05:50 PM [Apache] Status change detected: stopped
9:05:50 PM [Apache] Error: Apache shutdown unexpectedly.
9:05:50 PM [Apache] This may be due to a blocked port, missing dependencies,
9:05:50 PM [Apache] improper privileges, a crash, or a shutdown by another method.
9:05:50 PM [Apache] Press the Logs button to view error logs and check
9:05:50 PM [Apache] the Windows Event Viewer for more clues
9:05:50 PM [Apache] If you need more help, copy and post this
9:05:50 PM [Apache] entire log window on the forums
9:08:20 PM [Apache] Attempting to start Apache app...
9:08:20 PM [Apache] Status change detected: running

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