ipod not being recognized in iTunes?

I have a new iPod classic which I have registered through iTunes. I have had several iPods before, but now this one won't be recognized in iTunes. I have reset the iPod, restarted my computer. I tried to update my iPod a couple of weeks ago and had the same problem. My iPod is not showing up as a device on my account either, but it should pick up the device when connected. This new iPod is a replacement for an older classic model. The last time I had the old device attached to my account the device was corrupt (I figured after 7 years the hard drive had been exhausted). I don't see where that would impact the new model.