On desktop Right Click on start button and click on RUN.

In Run window type cmd

Command windows will open. Type DISKPART and then press enter.

At command promt type  :- Diskpart

To see all the available disks

Diskpart>  list disk

• Select disk 1 or disk 0   as required
  To list attributes of disk whether it is read only or not
  • Use command > attributes disk    

• To make flash drive writeable
  • DISKPART> attributes disk clear readonly
• To make flash drive readonly
  • DISKPART> attributes disk set readonly