How to make your usb drive readonly

This method will restrict the users not able to write in usb drives.
1. Open Run
2. Type regedit and press enter.
3. In Registry Editor, navigate to the following registry key:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control


4. Right click on control, navigate to new and create new key, Change the name as StorageDevicePolicies


5. Right click on it,navigate to new\DWORD and name it as WriteProtect
6. Right click on it, modify 0 as 1 in the value