Php – “could not find driver” error when using PDO with MSSQL server

This question has been asked many times and I've gone through all of them and none of the solutions have worked for me.

Basically,

I am getting "could not find driver" exception when connecting to MSSQL server using PDO. Below is my spec:

Windows 8 - 64 Bit version
MSSQL server 2008 R2 - 64 bit version
Wampserver 2.4 - 64 bit version with PHP 5.4 (Thread Safe version)

This what I have done so far:

1. Downloaded SQLSRV – version 3.0 from here
2. Placed the "php_pdo_sqlsrv_54_ts.dll" and "php_sqlsrv_54_ts.dll" files in "c:/wamp/bin/php/php.x.x/ext" directory (have used php_*sqlsrvts**.dll because I am using thread safe version of PHP)
3. Enabled them in php.ini ( I know there are two php.ini files in wampserver and I have edited this in the correct php.ini )
4. Restarted wampserver

But still I am getting the same error.

Can anyone please help me resolve this error?

Output of phpinfo();

Found following in the error logs of Apache:

PHP Warning:  PHP Startup: Unable to load dynamic library 'c:/wamp/bin/php/php5.4.12/ext/php_pdo_sqlsrv_54_ts.dll' - %1 is not a valid Win32 application.\r\n in Unknown on line 0
PHP Warning:  PHP Startup: Unable to load dynamic library 'c:/wamp/bin/php/php5.4.12/ext/php_sqlsrv_54_ts.dll' - %1 is not a valid Win32 application.\r\n in Unknown on line 0