Try doing this.
First try Running Registry Editor or “regedit”
ThenNavigate to the following registry key: -HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control
Now , Create a New Key named as StorageDevicePolicies.
Next , Highlight StorageDevicePolicies, and then create a New DWORD (32-bit) Value named as WriteProtect.
Finally ,Double click on WriteProtect, and set its value data to 1.
Then your done! 
You can try looking here : http://www.techyv.com/questions/how-remove-write-protection-flash-drive
