A USB flash drive cannot be used to store information until it has been formatted. You have a few methods to choose from when it comes to formatting. You can use FAT, FAT32 or NTFS formatting types by formatting the drive in Windows Explorer. Alternatively, you can format the drive using DOS if you like to work with the command prompt or if you have difficulty formatting the drive using the graphical interface.
Plug your flash drive into an empty USB port on your computer.
Click "Start," "All Programs," "Accessories" and "Command Prompt" to open the DOS command prompt window.
Type "diskpart" after the command prompt to start the Disk Partition utility. This should result in a DISKPART command prompt.
Type each of the following commands, one at a time, after the DISKPART prompt, pressing "Enter" after each:
list disk select disk # clean create partition primary select partition1 active format FS=NTFS assign exit
Close the command prompt window. Your USB drive is now formatted.
Back up your data before formatting.
You will lose any data on the flash drive when you format it.