Hi:

well, I have been able to intall knoppix using winxp and resizing the partitions without problem.

when knoppix has started from cd, you have to open konsole and then type:

#su
#knoppix-installer

This is a script that will guide you throw all the process. I think the best way is resize your XP partition and then create 2 partitions more. The first for your knoppix files, minimun 2.5G and you can choose ext3 or reiserfs type. Then when created this partitions knoppix will detect them and install every file in its corresponding location. It's easy, you can try, but if you don't want to create partitions, you can choose installing it in knoppix-like mode.