Hard drive help

Can anybody help? Knoppix wont let me write to or delete anything on my hard drive. is that a problem or will knoppix just not do that?

thanks in advance for helping the n00b.

3 Q: I see the partitions from my hard disk on the desktop and can access their contents when I click on them, but if I try to write to them I always get the error message "access denied". How can I write to my existing partitions?