Here I come again with a solution that works, instead of lame comments that don't solve anything... Like I did here:

http://www.knoppix.net/forum/threads...noppix-6/page2

I'm not going to address using the Knoppix distro as your desktop system, however to disable autologin on Knoppix 6.2, create a boot thumb drive - use the directions supplied in the link above. This will create a writeable portion of the bootable thumb drive filesystem called UNIONFS.

One you have done that simply edit the /etc/inittab file as follows:

Replace lines like this:

1:12345:respawn:/bin/bash -login </dev/tty1 >/dev/tty1 2>&1

With this:

1:12345:respawn:/bin/login </dev/tty1 >/dev/tty1 2>&1

Do this for all four tty entries and add tty5 and tty6 as well

Next change your default run level to 3 by changing id:5:initdefault to id:3:initdefault

Next make sure you set passwords for root and the knoppix user

as root

passwd root
passwd knoppix

Save the file and restart - you will now be booted into a console login screen which prompts for the username and password

Once you have logged in, boot into Xwindow if you so desire as follows

sudo /etc/init.d/knoppix-startx start

Whoo-hoo!