I have a external hard drive that was working fine until yesterday. I reformated my computer now it won't recognize the hard drive. I have removed it and put it on my son's computer, it says it's locating new hardware but won't show under my computer. It's binging when plugged in so it knows it's there. We have tried everything (bios, unplugging, restarting computer ect.) but nothing. Any suggestions? Thank you for any help you can give me.