If you find that you can't add or delete files to or from your USB drive, it's probably write-protected. Occasionally, USB drives can become write-protected due to a manufacturer setting or because of a fault in the disk. If you aren't prompted to enter a password to make changes to the files on the disk, you need to clear the write-protection using the Windows DiskPart utility. As a precaution, you should also reformat the drive to prevent the same thing from happening again. The process is the same on Windows 7, 8, 8.1 and 10.
Connect the USB drive to your computer while logged in with an administrative account. Right-click it in File Explorer and select Properties. Make a note of the drive's File System -- either NTFS or FAT32 -- and its capacity.
Copy all of the files to your computer's drive. Reformatting the drive is highly recommended, which deletes everything on the USB drive. Even if you don't plan to reformat the drive, using the Windows DiskPart Utility may still delete some files, so it's vital that you back up the files first.
Launch Command Prompt by typing cmd in Windows Search. Type diskpart in the Command Prompt window and press Enter. The DiskPart window opens.
Type list disk in the DiskPart window and press Enter. All of your connected drives are displayed. You can identify the USB drive by its size, which is the same as the capacity you noted in the File Properties window.
Select the USB drive by typing select disk, followed by a space and the disk number. To select Disk 1, for example, type select disk 1. Press Enter.
Type attributes disk clear readonly and press Enter. This clears all write-protection file attributes from the disk.
Formatting the Drive
Type clean and press Enter. This command deletes all volumes and partitions from the disk, which deletes all folders and files as well.
Type create partition primary and press Enter. This command creates a new partition so you can format the disk.
Format the disk in NTFS or FAT32 format, depending on how it was listed in the Properties window earlier. To do this, type one of the following commands and then press Enter:
- format fs:fat32
- format fs:ntfs
The progress of the format is displayed in the window, and DiskPart notifies you when the partition is complete. It takes about a minute to format a 1GB drive.
Type exit when the volume is formatted to close the DiskPart window. You can now copy or move the data you backed up back to the USB drive or add add new files to it.