Seriously annoying ipod problem?

This is a common problem with Windows. What has happened (I believe, out of my personal experience) is that your computer has corrupted the driver that is used in ociation with your iPod nano, which makes it foreign technology to your computer. If a disc came with your iPod, you should reinstall whatever was on it, and that should solve the problem. If not, I suggest reinstalling iTunes, or getting the new update of it.