How do I turn off read-only on my hard drive?

Disabling Read-Only With Diskpart

1. Type "diskpart" in the black Run window and press Enter.
2. Type "list disk" and press Enter.
3. Type "select disk d," replacing the "d" with the drive letter you are working on. …
4. Type "attributes disk clear readonly" and press Enter. …
5. Type "Exit" and press Enter to close the window.