How To Remove Write Protection From A Toshiba Usb Drive

I have tried setting HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\StorageDevicePolicies to make it writable, and I have tried running diskpart to clear the read only, I have also tried runningmUSBfixer to reformat the drive. None of the above appear to have made any difference, my drive is still read only. There is no external switch to write protect the device. Any other ideas on how to restore writability?