I have already seen http://dev.mysql.com/doc/refman/4.1/en/mysql-config-wizard-file-location.html
how to know mysql my.cnf location
and
http://dev.
You have to look I the folder C:\Program Files\MySQL\MySQL Server 5.5 but there is a problem. When you perform an MSI install of MySQL, my.ini is not created. There will be sample .ini files in that folder. In order to use one of them, say my-medium.ini, you need to do the following before a MySQL restart:
cd C:\Program Files\MySQL\MySQL Server 5.5
copy my-medium.ini my.ini
net stop mysql
net start mysql
Once, you do this, my.ini can be read by C:\Program Files\MySQL\MySQL Server 5.5\bin\mysql.exe.