How to format a write-protected USB flash drive or memory card
Some memory cards and USB pen drives have write protection switches, which allows you to prevent files from being deleted, or any new files being written to the device. It also prevents the drive or card from being formatted.Occasionally, you’ll find that a USB flash drive will refuse to format and Windows will tell you that it is write protected, even though there is no switch.Here are a couple of methods you can try to format the drive and remove the write protection.
In any version of Windows from XP onwards, run Regedit.exe
Navigate to the following key:
Computer\HKEY_LOCAL_MACHINE\SYSTEM\
CurrentControlSet\Control\StorageDevicePolicies
Double-click on the WriteProtect value in the right-hand pane of Regedit.exe. Change the Value data from 1 to 0 and click OK to save the change. Close Regedit and restart your computer. Connect your USB drive again, and you should find it is no longer write protected. You can now format the drive as normal by right-clicking on it in My Computer and choosing Format.If you can’t find StorageDevicePolicies, you can try creating a key by right-clicking in the white space in the Control folder and choosing New -> Key and carefully entering the name.
Now double-click on the new key (folder) and right-click once again and choose New -> DWORD. Name it WriteProtect and set its value to 0. Click OK, exit Regedit and reboot your computer.