Maybe you have IIS running too! it may conflict with the IIS port whihc is Port 80. try to stop it and try loading php file again. If it failed, try to press Ctrl-Alt-Del and look for the processes tab on the Task windows task manager. Try to find the apache.exe and mysqld-opt.exe, if they aren't there, apache and mysql is not running. Uninstall and reinstall xammp.
better yet, try this portable and stand alone Apache server.
http://myonline.webng.com/downloadpage.asp
read details before downloading
or
http://myonline.webng.com/inc/apachelite.zip
for direct download