If you need to disable or enable the writing permissions on your USB drives easily, USB Write Protect may be the tool you are looking for.
Write protect flash drive
USB Write Protect is a tiny application that will write protect your USB drives from accidental file deletion or modification.
This can prevent anyone from modifying the contents, make deleting the files or writing on to it impossible. It can also consequently prevent writing of, of virus, thereby making your flash drive more secure.
If any USB storage devices are already plugged in to your PC, you will have to first remove them, run this tool and then re-attach them.
USB Write Protect is a freeware portable Windows utility sized at only 11 KB only.