You are going at it completely wrong.

There are 2 ways I have made changes to write to the hard disk (do not try to write to NTFS partitions, you will destroy the partition).

  • 1) At a command promp, use the mount command to remount the partition as read/write. See man mount for details.

    2) From the desktop and the GUI: Right click on the partition icon. Select the actions ... sub-menu. Make the partition writeable.