I have a portable hard disk which at one time was installed in a PC and windows XP installed on it. Now I am using it as a backup and I want to delete the Windows directory from it, but when I try to delete the Windows directory I am getting an error that I cannot delete it. The hard disk is connected to my PC via USB. My PC boots from its own hard disk and has Windows Vista Business.
How can I delete these files from the portable hard disk?