Note:This topic was updated for 9.3.1.

ArcGIS Desktop (ArcEditor and ArcInfo), ArcGIS Engine, and ArcGIS Server Workgroup come with an executable file that installs SQL Server Express and enables the SQL Server Express instance to store ArcSDE geodatabases.

These geodatabases use the ArcSDE direct connect libraries installed with the ArcGIS Desktop, ArcGIS Engine, or ArcIMS client to connect from the client application to the SQL Server Express database.

You must have administrative privileges on the computer on which you want to install SQL Server Express. Users with administrative privileges on the machine automatically have administrator privileges in the database server except when SQL Server Express is installed on a machine with a Windows Vista or Windows 2008 Server operating system. During installation, a database server administrator can be added to the instance.

By default, SQL Server Express uses up to 1 GB of memory. It relinquishes memory as other applications request it. That means, if you only have 1 GB of memory on the computer on which SQL Server Express and ArcGIS Desktop or ArcGIS Server Workgroup are installed, you might encounter slower performance. If you find this to be true, you might want to increase the amount of random access memory (RAM) on the computer.

Installation for ArcSDE for SQL Server Express is a two-step process:

1. Install Microsoft SQL Server Express Edition with Advanced Services.
The setup program provided with ArcGIS Desktop, ArcGIS Engine, and ArcGIS Server Workgroup installs Microsoft SQL Server Express 2008 with Advanced Services. SQL Server 2008 Express requires Windows Installer 4.5, .NET 3.5 SP1 Framework, and Windows Powershell 1.0 to be installed on the computer before you can install SQL Server Express. If you do not, the SQL Server Express installation will not proceed. These programs can be obtained from the Microsoft Web site.
Once you have installed the prerequisite applications, run the SQL Server Express with Advanced Services installation. Be sure to read the installation guide provided in the ArcGIS Desktop, ArcGIS Engine, or ArcGIS Server Workgroup media for instructions on what settings to use in the wizard.
You will have an instance of SQL Server Express with Advanced Services running on the computer when you finish the SQL Server Express installation. This instance is referred to as a database server in ArcGIS Desktop.
2. Continue with the wizard to configure the SQL Server Express instance to use ArcSDE geodatabases, add an administrative user to the database server, authorize the software (ArcGIS Server Workgroup only), and configure SQL Server Express to support remote connections.
Each server machine on which the workgroup database server is installed requires an authorization file. To obtain this, contact your ESRI representative.

At this point, no geodatabases have been created; you just have an instance of SQL Server Express that is ready to store ArcSDE geodatabases. Your next step is to add the database server to the Catalog tree. Similar to adding a mapped drive for file-based data or adding a database connection for ArcSDE geodatabases, you must do this for every connecting client that needs to administer the database server or the geodatabases stored on it.

To learn how to add a database server to ArcCatalog, see Adding an ArcSDE database server.

Tips A list of the prerequisite software and minimum and recommended hardware and software requirements for running Microsoft SQL Server Express with Advanced Services can be found at the Microsoft support site: http://msdn.microsoft.com/en-us/library/ms143506.aspx 32-bit versions of SQL Server Express with Advanced Services and ArcGIS Desktop (which is a 32-bit application) both run on certain 64-bit computers. For SQL Server Express on a 64-bit computer, you need the 64-bit version of the .NET Framework. For details on supported platforms and requirements for SQL Server Express, consult the Microsoft support site. For information on supported platforms for ArcGIS Desktop, see the ESRI support site.