I just updated the csih service installation helper package to 0.9.8-3. This bugfix release is supposed to address the problem adding a user account to the Administrators group if /etc/group contains a "root" group. The script arbitrarily adding the "root" group will be changed soon, too.
Have fun, Corinna -- Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Maintainer cygwin AT cygwin DOT com Red Hat