Locating my.ini (MySQL configertion file) for MySQL 5.6 in Windows

File Name Purpose
%PROGRAMDATA%MySQLMySQL Server 5.6my.ini,%PROGRAMDATA%MySQLMySQL Server 5.6my.cnf Global options
%WINDIR%my.ini, %WINDIR%my.cnf Global options
C:my.iniC:my.cnf Global options
INSTALLDIRmy.iniINSTALLDIRmy.cnf Global options
defaults-extra-file The file specified with --defaults-extra-file=path, if any
%APPDATA%MySQL.mylogin.cnf Login path options

http://dev.mysql.com/doc/refman/5.6/en/option-files.html