Get php_mysql extension to work on ISS 7.5 on Windows Web Server 2008 R2 x64

So steps to get php_mysql extension loaded:
1. in php.ini, make sure extension_dir points to where php_mysql.dll is.
2. in php.ini, enable extension=php_mysql.dll
3. copy C:\php\libmysql.dll to C:\Windows\SysWOW64

That does it for me.

UPDATE:

php.ini must be the in windows directory.