Can't get Knoppix to boot from CD, laptop still tries to load XP

[Capricorny]

Re Knoppix 6.2: Generally, a newer version will be better, because hardware support is improved to a larger extent than it is dropped/new bugs introduced etc. (There are exceptions, though!) But I'd guess 6.2 would be quite fine for an XP laptop.

The most robust, but of course not easiest way to access the files, is to take the hard disk out, mount it in an external cabinet and access them from there. The replace it in the pc. I'm pointing to this partly because the important files should have been backed up to external media already, so this could be a way for you to get backup in place.

Otherwise, whenever a PC is able to boot from USB, that will be the easiest way to use Knoppix for maintenance, as cheech suggests.
Good luck!