Installing the Microsoft Drivers 3.0 for PHP for SQL Server

I'm running WebMatrix 2.  I've already enabled PHP (Version 5.3.13) and it's running fine.

Now I want to install the Microsoft Drivers 3.0 for PHP for SQL Server

I consulted the Driver Versions table at http://msdn.microsoft.com/en-us/library/cc296170(v=sql.105).aspx but I'm not sure which pair I should use:

php_sqlsrv_53_nts_vc6.dll
php_pdo_sqlsrv_53_nts_vc6.dll

or

php_sqlsrv_53_nts_vc9.dll
php_pdo_sqlsrv_53_nts_vc9.dll
 
You have to install both the php_sqlsrv... AND the php_pdo_sqlsrv... file, right?

The php5.dll file is in C:\Program Files\IIS Express\PHP\v5.3 but according to phpinfo the extension_dir is
C:\Program Files\IIS Express, so that's where I should install the dll files, right?

Thanks in advance for any help.

Christian Bahnsen