Go to Program Files/Origin Games/Battlefiend 3 and delete the PB Folder
Launch Origin as Admin
Right Click BF3 and Choose Repair

Wait for repair to complete

Now go back to Program Files/Origin Games/Battlefeind 3/PB and copy contents

Overwrite contents here

C:\Users\Your UserName\AppData\Local\PunkBuster\BF3

YourUsername is your computer account name, btw..

AppData is hidden so if you're not sure how to view hidden files..

http://maketecheasier.com/display-hidden-files-and-folders-in-windows/2009/09/05