Please don't be anxious when running into such a situation, for we know how to fix external hard drive needs formatting issue as well as the way to recover data from formatted hard drive. Facing such a situation, what should you do? Are you going to format the hard drive as you are told? In fact, not formatted error not only happens on external hard drive but also appears on almost all storage devices such as hard disk drive, USB flash drive, pen drive, floppy disk, memory card, memory stick and so on. Phenomena: After you have plugged your external hard drive into a computer, you can't open it to access the files because Windows pops up an error message which reads ' You need to format the disk in drive before you can use it' OR ' The disk in drive is not formatted (appears in Windows XP)'.