Best Answer
1. Have you made any changes on the computer prior to the issue?
2. What happens when you try to use the pen drive in different computer?
3. Do you have any security software installed on the computer?
This might be caused due to virus on the computer.
Perform the following troubleshooting methods:
Method 1:
Download any try version of good commercial antivirus (i.e Quick Heal)
Method 2:
Run the fix it from the link “Diagnose and repair Windows File and Folder Problems automatically” and check if this fixes the issue
by following the official website of microsoft :
http://support.microsoft.com/mats/windows_file_and_folder_diag/en-us
Method 3:
open cmd (by pressing "Windows+R" and then type cmd presss ENTER) and then type the following command in command prompt
attrib –r –a –s –h /s /d K:\*.*
where K is the dirve letter of your pen drive
!!..Good Luck..!!