If the server to be upgraded already runs a Netspan version using SQL Server 2000, DO NOT UNINSTALL SQL SERVER 2000 before installing SQL Server 2005. Netspan’s installation program needs the two products to run "side-by-side" in order to automatically migrate the database from SQL Server 2000 to 2005. The migration is handled in the section Server Installation.
Run the executable from your installation DVD:
Accept the Licensing terms and click 'Next'
Click 'Next'
Click 'Next'
On the Next Screen enter your company name and your name and click 'Next'
Select SQL Server 'Database Services' and click the 'Advanced' button
Expand the 'Client Components' node, click on the 'Management Tools' item and select 'Will be installed on the Hard Drive', then click 'Next'
If you are asked to enter an instance's name, type 'SQLSERVER2005', otherwise select the 'default instance' radio button
Select 'use the built-in System Account' radio button and the 'Local system' account in the drop-down list, then click 'Next'
Click 'Next'
Click 'Next'
Click 'Install'
Click 'Next'
Click 'Finish'
Reboot the machine
Apply the latest 'Service Pack' for SQL Server 2005 (can be found either on Microsoft’s website or in the Image\PreInstall directory)