Tableau Server on Windows Help

To automatically authenticate your users when the workbook they're accessing connects to a live, Windows-authenticated data source, configure your Tableau data connection with the Use Windows Authentication option selected:

Windows Authentication		Username and Password
Authenticates with the server’s Run As user service account		Each Tableau Server user is prompted for database credentials

It's important to understand how the Run As service account accesses data on behalf of the users in your organization. In some cases, users may inadvertently access data that their users accounts are not explicitly permissioned for. Before allowing users to access data with the Run As service account, review Data Access with the Run As Service Account.