Pheewww! Calm down, will you ?-)

The latest release is KNOPPIX_V3.3-2003-11-19-EN.iso
The "Get Knoppix" link at the top of this very page will show you a list of
mirrors; pick one close to home. The garbage you're seeing must be your
browser displaying the raw ISO. You should do "save as" and point to a disk
area with at least 700Mb free space. Then burn the ISO file as is to a CD.
If you're using Nero, that's "File/Burn Image".

Then take some time to get acquainted with the live system before attempting
partitioning your HD and installing (that's done with the knoppix-installer script).

Sit back, have a look at the FAQs and docs, enjoy the ride.