I am facing the same problem. I have just installed xampp v3.2.1. It's running the apache successfully after allowing it through windows firewall but MySQL doesn't work. Here is the whole detail. It would be really kind if any of you share the solution with me too.
8:36:45 PM [mysql] Problem detected!
8:36:45 PM [mysql] Port 3306 in use by ""C:/Program Files/MySQL/MySQL Server 5.6/bin\mysqld" --defaults-file="C:\ProgramData\MySQL\MySQL Server 5.6\my.ini" MySQL56"!
8:36:45 PM [mysql] MySQL WILL NOT start without the configured ports free!
8:36:45 PM [mysql] You need to uninstall/disable/reconfigure the blocking application
8:36:45 PM [mysql] or reconfigure MySQL and the Control Panel to listen on a different port
8:36:45 PM [mysql] Attempting to start MySQL app...
8:36:45 PM [mysql] Status change detected: running
8:36:48 PM [mysql] Status change detected: stopped
8:36:48 PM [mysql] Error: MySQL shutdown unexpectedly.
8:36:48 PM [mysql] This may be due to a blocked port, missing dependencies,
8:36:48 PM [mysql] improper privileges, a crash, or a shutdown by another method.
8:36:48 PM [mysql] Press the Logs button to view error logs and check
8:36:48 PM [mysql] the Windows Event Viewer for more clues
8:36:48 PM [mysql] If you need more help, copy and post this
8:36:48 PM [mysql] entire log window on the forums
[EDIT by Altrea: splitted from original topic because unrelated]