In Windows 2003 Server SP1, Microsoft changed the default rights for access to the Service Control Manager to administrator-only. Prior to that, non-admin users could enumerate services and read their status. The user defined in the NT Services & WMI panel of Server Settings is the one that actually attempts to open the SCM on the target host. If this user is a member of the the admin group on the target system the probe should work.

If the InterMapper service is running as an admin user, that will override the credentials specified in the NT Services & WMI panel. Normally, InterMapper runs as the Local System account, so then those credentials are significant. In fact, they exist solely so InterMapper does not need to run as admin. On the few occasions when admin status is required, InterMapper impersonates the user defined in the Server Settings.