Just follow the below steps …..

Click on "Start" -->Run --> type cmd and click on OK. Here I assume your pen drive letter as K: Enter this command.

attrib -h -r -s /s /d k:\*.*

You can copy the above command --> Right-click in the Command Prompt and paste it. Note : Don't forget to replace the letter k with your pen drive letter. Now press "Enter". That’s it!!!!

Sorry english!!,just copy n paste =]
credit:Macho Cyb3rs3c