Change the Service Startup Account for SQL Server 2008

To change the SQL Server service startup account

1. On the Start menu, point to All Programs, point to Microsoft SQL Server 2008 R2, point to Configuration Tools, and then click SQL Server Configuration Manager.
2. In SQL Server Configuration Manager, click SQL Server Services.
3. In the details pane, right-click the name of the SQL Server instance for which you want to change the service startup account, and then click Properties.
4. In the SQL Server <instancename> Properties dialog box, click the Log On tab, and select a Log on as account type.
5. After selecting the new service startup account, click OK.
   A message box asks whether you want to restart the SQL Server service.
6. Click Yes, and then close SQL Server Configuration Manager.