WordPress and SQL Server

Hi All,
I have done a manual deployment of WordPress on a Windows 2008 Server R2.
PHP on its own is functioning, however trying to render http://localhost/wordpress/wp-admin/install.php gives me a error about mysql.
Your PHP installation appears to be missing the MySQL extension which is required by WordPress.
Am I required to have MySQL working even tho I will be using a SQL server?
I have already edited the config file to point the config to the remote SQL server with its user login/password.
Any help regarding WordPress and SQL server and this error would be greatful.
I have read articles about uncommenting the mssql.dll in the php.ini, but I am curious if this is required if I am not using mysql.
Thanks
Darian