How to disable / prevent write to usb?

There is a time when your computer caught virus and you want to copy files from usb stick to your hard drive to fix problems and you don't want to transfer virus to your usb drive. The following are the steps to secure your usb drive.
 
1. Click Start button
2. Click Run
3. Type "Regedit"
4. Navigate to:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control

5. Click Edit in the menu 6. Click New to create a key with the name "StorageDevicePolicies".
7. In left side panel, select "StorageDevicePolicies" key, right click to create new DWORD value then label it "WriteProtect". Set its value to "1". If you want to enable writing again, just change its values to "0".
8. Close the registry editor and restart your computer for any changes to go into effect.