how to remove right protection from pendive

It causes due to many reasons....

(1)First of all the main cause of this problem maybe a strong virus.....

(2) Follow these steps:
 a) Open Start Menu>Run>type regedit and press Enter;now u find a window of registry editor.

 b) Now go through the following path:

 HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\StorageDevicesPoilcies

c) Double Click the Key WriteProtect in the right pane & set the value from 1 to 0 in the value
    data box and press OK button.

d) At Last just exit registry, restart your computer and then again re-connect your USB pen drive
    on your computer.that it is, done .

     Even now if ur not able to get out of it then just try the next method
    1. Shutdown the computer system
 
    2. Insert Pen drive into the computer.
 
    3. Turn on the computer and then immediately start pressing F8 key. Advanced Boot Options                           screen will  appear on the screen.

    4. Select Safe Mode with Command Prompt
 
    5. After loading files, suppose, if your Pen drive letter is H , then write as

    6. C:\windows\system32>H: and press enter

    7. H:\>format H: and press enter

    8. Press Y when (Y/N) prompt appears and press enter

    9. This will start full formatting of the pen drive which will remove write protection from the Pen drive.