Steps to make your drive Write Protected:
1. Open Registry Editor by typing regedit in Run dialog.
2. Navigate to the key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\
3. Find a sub key inside it named “StorageDevicePolicies”. If it does not exist there then we need to make it. Right click on “Control” key -> New -> Key. Name it “StorageDevicePolicies” without quotes.
4. Now right click on this newly created key and then click New -> DWORD value and name it as “WriteProtect”.
5. Modify this key and give it a value 1.
6. Click OK, and remember to restart the PC.
Now no more data can be transferred to the drive but to start using the drive again just give the “WriteProtect” key a value of 0 instead of 1 and restart the PC.