Not authorized...

[Karibu]

Thanks for the response, Joselb, I checked /etc/fstab of the USB-installation and compared it with /etc/fstab of the HD installation and I did not find a difference except the line for sdc1 which is the HD partition where Knoppix is installed. The difference is only that /dev/sdc1 is / and not /media/sdc1.
This is the fstab of the HD install.

# DEFAULT BASE FSTAB, UNCONFIGURED
proc       /proc         proc       noauto             0 0
sysfs      /sys          sysfs      noauto             0 0
/dev/sdc1 / reiserfs relatime 0 0
/dev/sdb3 none swap defaults 0 0
/dev/sdc2 none swap defaults 0 0
# Added by KNOPPIX
/dev/sda1 /media/sda1 ntfs noauto,users,exec,umask=000,uid=knoppix,gid=knoppix 0 0
# Added by KNOPPIX
/dev/sda7 /media/sda7 ext4 noauto,users,exec 0 0
# Added by KNOPPIX
/dev/sda6 none swap defaults 0 0
# Added by KNOPPIX
/dev/sda2 /media/sda2 ntfs noauto,users,exec,umask=000,uid=knoppix,gid=knoppix 0 0
# Added by KNOPPIX
/dev/sda3 /media/sda3 ntfs noauto,users,exec,umask=000,uid=knoppix,gid=knoppix 0 0
# Added by KNOPPIX
/dev/sdc4 /media/sdc4 ntfs noauto,users,exec,umask=000,uid=knoppix,gid=knoppix 0 0
# Added by KNOPPIX
/dev/sr0 /media/sr0 auto noauto,users,exec 0 0
# Added by KNOPPIX
/dev/sdb2 /media/sdb2 ext4 noauto,users,exec 0 0
# Added by KNOPPIX
/dev/sdd /media/sdd auto noauto,users,exec 0 0
# Added by KNOPPIX
/dev/sde /media/sde auto noauto,users,exec 0 0
# Added by KNOPPIX
/dev/sda5 /media/sda5 ext4 noauto,users,exec 0 0
# Added by KNOPPIX
/dev/sdf /media/sdf auto noauto,users,exec 0 0
# Added by KNOPPIX
/dev/sdb5 /media/sdb5 ext4 noauto,users,exec 0 0 

I'm not knowledgeable enough to figure out what could be wrong. Could you please help?.