dell inspirion 15 sumthing, windows 8 pro, yes formatted when i first got it, installed drivers & it worked fine on this computer but with os windows 7, then my cord got messed up the 1 that plugs in the usb port so i purchased another 1 brand new same cord, by the time i got a new cord i switched os to windows 8 pro, i plug it in it makes the noise that its plugged in then i get a message saying cpu doesnt recognize it, i go to disk management it says there & working properly!!!