http://bugs.winehq.org/show_bug.cgi?id=20643
--- Comment #23 from Urmas dwqwt3i02@sneakemail.com 2009-12-04 07:28:32 --- The Users group implicitly includes all users with 'limited' users accouts, plus BUILTIN\INTERACTIVE and BUILTIN\AUTHENTICATED groups both on XP and Vista. So all local users, administrators, network users etc. are members of Users group, and Wine should correctly emulate this behaviour. User not in Users group isn't a WoW bug, it's abnormal condition.