About two months ago, I installed Debian Jessie (8.1) to the another second-handed laptop PC. During the install process, I made a non-root normal user account as the installer guided me. One day, I wanted to add another normal user. Because the Debian system recommendation is to use adduser command, I reviewed its usage and functions. Then I found that the groups to which the initial account belonged were different from the adduser command default groups. I feel peculiar at first, and added the following line to /etc/adduser.conf EXTRA_GROUPS="dialout cdrom floppy audio dip video plugdev netdev lpadmin scanner bluetooth" Then the following command works as expected: adduser --add_extra_groups [new uid] I guess if the tasksel changes the extra-groups default parameters depending on the the purpose of the installation, it is more convenient to the users, at least, to me.