Disable USB mass storage access on client machines

You have to do this steps as bellow:

  1. Go to the client machine and
  2. go to start button and type in to search box gpedit.msc
  3. then your group policy window will open
  4. left side of window - search Administrative Templates and double click on it
  5. then click on System
  6. next you will see Removable Storage Access just click on it
  7. then you will see lots of group policy name
  8. see the All Removable Storage Access: Deny All Access
  9. double click on it and select the option Enable and click on OK button
  10. you will success to block USB of client

The link you shared has this comment: you can use the below GPO. User Configuration \ Administrative Templates \ System \ Removable Storage Access \ All Removable Storage classes: Deny all access.

Have you tried it?