Sorry for not getting back to you sooner. To fix this problem please follow these steps:
You sound like an advanced user, but going to give detailed instructions anyway
Start an elevated command prompt and then run diskpart.
Use the list disk
command again to confirm that we are working with the right disk. When you have determine the driver number associated with your USB drive, type select disk <number>
and press enter. So if the usb drive is listed as Disk 6, you would like select disk 6
When you press enter it should state that the disk is selected. To clear the drive, now type clean
. This command will remove all partitions.
You can now type exit
to get out of the diskpart utility. Now open up the Computer
screen and format the USB drive.
Let me know if this allowed you to get past the write protect warning.