Can't add the first administrator

Completed first installation of Foswiki on IIS (Win 2003) with Active Directory for authentication - following instructions in FoswikiOnWindowsIISAndPerl

Seems I have a working system - I can login OK as a domain user or as the administrator, and can view/add/edit wiki pages, but I can't join the admin group.

• If I try internal admin login an HTTP 400 error - Bad request is returned
• If I try to edit the Administrator Group (change) access is denied

Removing integrated windows authentication & allowing anonymous login, changing LoginManager settings, etc., in configure.pl have no effect. File read/write privelages appear OK.

Sorry - newbie question - but what should I be looking at to solve this?

Solved - the Domain administrator name was the problem. With windows integrated authentication the effective Foswiki login name was DOMAIN_NAME\administrator. I enabled the LoginNameAliasesPlugin with the REMOVE_PREFIX extension to strip out the DOMAIN_NAME\ prefix and changed the AdminUserLogin name in configure to match the domain admin name.