* *nix: PHP with mssql extension and [FreeTDS](http://freetds.org)
* Windows: PHP with [SQL Server Driver for PHP](http://www.microsoft.com/downloads/en/details.aspx?displaylang=en&FamilyID=ccdf728b-1ea0-48a8-a84a-5052214caad9) "sqlsrv" 2.0+
Note: [SQL Server 2008 R2 Express](http://www.microsoft.com/express/Database/) can also be used which is provided free by Microsoft. However, it has limitations such as 10GB maximum database storage.
The easiest way to get up and running with SQL Server on SilverStripe is using the installer:
* Visit [http://www.silverstripe.org/microsoft-sql-server-database/](http://www.silverstripe.org/microsoft-sql-server-database/) and download the latest stable version
* Extract the contents so they reside as an **mssql** directory inside your SilverStripe project code
* Open the installer by browsing to install.php, e.g. **http://localhost/silverstripe/install.php**
* Select **SQL Server 2008+** in the database list and enter your SQL Server database details
A: Please ensure you have enabled TCP access using **SQL Server Configuration Manager** and [opened firewall ports](http://msdn.microsoft.com/en-us/library/ms175043.aspx).
A: Sometimes SQL Server will be installed as a non-default instance name, e.g. "SQLExpress" instead of "MSSQLSERVER" (the default.)
If this is the case, you'll need to declare the instance name when setting the server in your PHP database configuration. For example: **(local)\SQLExpress**. The first part before the slash indicates the server host, or IP address. In this case, (local) indicates localhost, which is the same server PHP is running on. The second part is the SQL Server instance name to connect to.
A: If you are using FreeTDS make sure you're using TDS version 8.0 in **/etc/freetds/freetds.conf** (or wherever it's installed). If on Windows, ensure you use the [SQL Server Driver for PHP](http://www.microsoft.com/downloads/en/details.aspx?displaylang=en&FamilyID=ccdf728b-1ea0-48a8-a84a-5052214caad9) and **NOT** the mssql drivers provided by PHP.
**Note**: Certain distributions of Linux use [SELinux](http://fedoraproject.org/wiki/SELinux) which could block access to your SQL Server database. A rule may need to be added to allow this traffic through.