So I bought an exterior hard drive for the purpose of backing up my computer. The exterior hard drive is in the format exFat. I tried running the File History backup, and it eventually failed. Ever since then, almost every time I plug that hard drive into my computer, it comes up with "There is a problem with this drive, please scan now", or something of that ilk. Also, every time I try to copy any file over to the hard drive, I get "Invalid MS-Dos function" or something or this error: The backup did successfully insert a lot of files at first, but now I can't delete or add any files to the hard drive. I bought another of the same drive, and the same thing happened. Does anyone know what I should do, or is the drive toast, and I should just get another one?