In Services, right click the service you want to configure, and click Properties.
Select the required startup option i.e Automatic
Then click the Log On tab, then either System Account or this Account.
If you click This Accocunt, click Choose User, specify a user account and then the password for that account.
To provide a user interface on the desktop that can be used by anyone who is logged on when the service is started, select Allow service to interact with desktop.
Remember to do this you must be logged in as an Adminstrator.