Help for a Linux dummy!

We have a thinkpad which does not recognize its Windows system on the harddisk. We booted Knoppix 5.2 sucessfully and can read the harddisk contents, and a stick attached to the USB port. However, when we try to transfer disk files to the stick we get the message that this is not permitted. We cannot change the read-only status by right-clicking on the device symbol for the stick on the desktop. Obviously, we are allowed to read only. How can we change this?

Would be very thankful for any information.

Hobe