How to disable writing to USB?

How to disable writing to USB?:

If you are the administrator of public cafe or school,this trick will be helpful for giving protection to your system.  You can disable writing to USB.  This will prevent from file stealing.  You have to login to administrator so that you can access regedit.

Go to start .  Select run.

Type as regedit and hit enter
Now navigate to

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\StorageDevicePolicies

 In right panel you can find writeprotect
Change the value to 00000001


That's all now no  one can transfer data to USB.  Now your system is protected.