1. Remove the write protection: http://www.ghacks.net/2011/03/18/how-to-enable-write-pr...
Format this USB drive:
2. Right click “My Computer” =>Select “Manage”=> Choose “Disk Management” => Right click your drive on the list => format it. Note: You should back up your important data well before you format this drive.
Cannot access the data? You could try a free USB drive recovery tool to get back your data and then format it afterwards.