maxtor 20gig HDD

I read XP can overwrite Knoppix files (being the superior OS that it is) so Installed windows Xp pro to a 11Gig partitiion first...

now when I try to install knoppix, i select my HDD in the partition program and it tells me that its read only and cannot access it.
Is there a reason for this? Whats wrong?

thats aas far as I can get so far...