SQLSRV driver installed but shows error while connecting to MSSQL 2008 R2 db using PHP

Question

I have a laptop running with windows 7 Professional, MSSQL 2008 R2 and IIS 7.5. The system has all my applications in c# and php running successfully. Now I wanted to transfer all my files and apps on a 2nd laptop with windows 7 Ultimate. But for some reason I just cannot get a successful connection to my db even though phpinfo() shows sqlsrv installed and I am using the exact same code just changing the connection string of the DB.

I have MSSQL management Studio v 10.50.2500
IIS v 7.5.7600.16385
PHP v 5.5.3
SQLSRV Driver for php 5.5 (its not an official MS release , but its quite popular and works on my previous laptop )

I am getting an error like :

    Array (
    [0] => Array (
                 [0] => IMSSP [SQLSTATE] => IMSSP 
                      [1] => -49 [code] => -49 
                      [2] => This extension requires the Microsoft SQL Server 2012 Native Client. Access the following URL to download the Microsoft SQL Server 2012 Native Client ODBC driver for x86: http://go.microsoft.com/fwlink/?LinkId=163712 
                      [message] => This extension requires the Microsoft SQL Server 2012 Native Client. Access the following URL to download the Microsoft SQL Server 2012 Native Client ODBC driver for x86: http://go.microsoft.com/fwlink/?LinkId=163712 
                       ) 
          [1] => Array (
                       [0] => IM002 [SQLSTATE] => IM002 
                       [1] => 0 [code] => 0 
                       [2] => [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified 
                       [message] => [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified 
                       )
          )

my PHP code is as follows (which i know for a fact it works on the first laptop) :

    `$serverName = "DELL-PC"; //serverName\instanceName`
    ``
    `$connectionInfo = array( "Database"=>"amlTest");`
    `$conn = sqlsrv_connect( $serverName, $connectionInfo);`

I just cannot figure out what is the problem or where am I missing out? I really need this working!! and have spent far too much time re-installing all my softwares and trying out all php versions.
I hope its not because of the difference in windows version

Also, Sorry if I have made any mistake formatting my question, as this is my first post.

Answer 1

Have you installed the feature pack?

http://microsoft.com/en-us/download/details.aspx?id=29065

A hint from the error tells us that you need the 2012 version of the MS SQL Server for this to work. Also make sure your Server permissions are set correctly.