SQL Server Express users: click Existing Components (SQL Server Express) for information that is specific to SQL Server Express Setup.
Use the Existing Components page of the Microsoft SQL Server Installation Wizard to view a list of SQL Server components installed on the computer where SQL Server Setup is running.
Click the Details button to see a report that lists the maintenance and upgrade options available for each currently installed SQL Server component.
Maintenance: Component maintenance is provided through Add or Remove Programs in Control Panel.
Upgrade: Existing components can be upgraded to SQL Server 2005.