Disable USB Mass storage Devices in windows

To Disable the Use of USB Storage Devices
To
disable the use of USB storage devices, use one or more of the
following procedures, as appropriate to your situation: If a USB
Storage Device Is Not Already Installed on the Computer
If a USB
storage device is not already installed on the computer, assign the
user or the group Deny permissions to the following files:
·%SystemRoot%\Inf\Usbstor.pnf
·%SystemRoot%\Inf\Usbstor.inf
When
you do so, users cannot install a USB storage device on the computer.
To assign a user or group Deny permissions to the Usbstor.pnf and
Usbstor.inf files, follow these steps:
1. Start Windows Explorer, and then locate the %SystemRoot%\Inf folder.
2. Right-click the Usbstor.pnf file, and then click Properties.
3. Click the Security tab.
4. In the Group or user names list, click the user or group that you want to set Deny permissions for.
5.
In the Permissions for UserName or GroupName list, click to select the
Deny check box next to Full Control, and then click OK.Note In
addition, add the System account to the Deny list.
6. Right-click the Usbstor.inf file, and then click Properties.
7. Click the Security tab.
8. In the Group or user names list, click the user or group that you want to set Deny permissions for.
9.
In the Permissions for UserName or GroupName list, click to select the
Deny check box next to Full Control, and then click OK.
If a USB Storage Device Is Already Installed on the Computer
Important
This section, method, or task contains steps that tell you how to
modify the registry. However, serious problems might occur if you
modify the registry incorrectly. Therefore, make sure that you follow
these steps carefully. For added protection, back up the registry
before you modify it. Then, you can restore the registry if a problem
occurs.
If a USB storage device is already installed on the computer, set the Start value in the following registry key to 4:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\UsbStor
When
you do so, the USB storage device does not work when the user connects
the device to the computer. To set the Start value, follow these steps:
1. Click Start, and then click Run.
2. In the Open box, type regedit, and then click OK.
3. Locate, and then click the following registry key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\UsbStor
4. In the right pane, double-click Start.
5. In the Value data box, type 4, click Hexadecimal (if it is not already selected), and then click OK.
6. Quit Registry Editor.

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