Here are the VIs we use for Windows authentication and domain groups. Validate Username and Password.vi takes the username and password and returns a TRUE if it validates against the domain controller. User in Group.vi takes a username (or current user if left blank) and a Domain Group name and returns TRUE if the user is a member. User Groups.vi takes a username (or current user if left blank) and returns an array of Domain Groups to which the user belongs. We only use these on our internal