ipod doesn't show up in itunes or even in my disc utility..

So I have an Ipod classic 160gb and the "Use itunes to Resore" picture showed up on my screen. When i plugged it into my laptop the device didn't show up in my itunes or even on my laptop. The ipod's screen is frozen and reads "do not disconnect". What should I do? I've updated my itunes and software, tried using a new usb, restarted my laptop, nothing seems to work.... 😢