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