I’ve been using my 250gig WD hard drive for months now and all of a sudden when I went to go access it toady my computer doesn’t even recognize it exists. I tried unplugging it and plugging it back in using different USB ports but it still won’t recognize it. I also tried restarting my computer but to no avail. I know the USB port works becuase I tried accessing other hardware on them and it worked. Any suggestions?