Knoppix is a Live CD/DV, there would be little point in password protecting it. If you want an installed Linux system similar to Knoppix you would be better off installing Debian than fighting with a Knoppix "install". People have indeed forced Knoppix to install, in some cases with less problems than others, but it was not intended for install to hard disk.

The Adrian version is targeted at sight impaired. While it can be used by anyone, if you have normal vision you might want to download and burn a version of Knoppix without Adrian in the name. Most people are happier without the Adrian version. See the documentation link near the top of this page and read the downloading faq before downloading Knoppix and making a disc.