Useful Trick For Disabling Write Access To Removable USB Mass Storage Devices

USB drive is a removable mass storage device which is generally used to store and transfer data. This portable storage device is lightweight and handy to use which makes it a more preferred storage option as compared to CD, zip drive disk or floppy disk.

It is possible that you disable USB (Universal Serial Bus) drive’s access to the various USB mass storage devices such as USB key, pen drive, portable hard disk, flash drive and thumb drive while allowing the USB hardware devices such as keyboard, printer, mouse, webcam and scanner linked to USB ports to work normally, using a registry hack.

However, this registry hack disables the access to USB drive completely preventing the user from copying data to USB disk storage and reading files/ documents from USB storage device.

If you wish to disable only the write access to external removable USB disk drive, you need to use a different registry hack of registry entry “WriteProtect” in the registry key “StorageDevicePolicies” for restricting Windows from writing onto the USB drive, thereby preventing the user from copying any sensitive information from the computer to the USB drive.

This registry hack works in a manner very much similar to write-protect aspect used in backup tape and floppy disk which makes the disk “read-only”. However, the system wide implementation of this registry trick blocks any recording/ writing of data to the removable USB device.

Just follow the simple steps mentioned below for disabling write access to all USB drives and allowing read-only access only:

1> Choose “Run” option from the Start Menu. Type “regedit” into the run command box and press “Enter” to open the “Registry Editor”.
2> Locate the registry key mentioned below:


3> Then create a new registry key and name it as “StorageDevicePolicies
4> Select and highlight the key “StorageDevicePolicies” and create a new DWORD value. Name it as “WriteProtect”.
5> Double-click on “WriteProtect” and fix its value data as ‘1′.

Once the setting is done, no user on the PC will be allowed to copy, transfer or write any data or files/ documents to the USB drives. If you attempt to copy or download files from the computer to the removable USB drive, an error message will appear notifying you that the disk and media is write-protected and you need to either utilize another disk or eliminate the write protection.
If you wish to revert the setting or enable write access to all USB drives in future, you simply need to delete the registry key “StorageDevicePolicies” or the registry entry “WriteProtect” or alter the “WriteProtect” value data to 0.

For some reason, if you do not want to edit the registry manually, you can download the below mentioned registry registration files in order to enable/ disable write protection (or block the attempt to write) to the USB removable drive.

DisableWriteToUSB.reg (to be extracted from

EnableWriteToUSB.reg (to be extracted from

Double-click on the .reg file once it is extracted from .zip archive and merge the registry entries.

This trick works well with most Windows operating systems including Windows Vista, XP SP2 & 3, Server 2008 and 2003.

Related post:

1> How to enable write protected USB.


  1. Neither of the links are working correctly. Please correct it as I accidentally deleted the files long time back when I had it. Thanks!


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