I'm using Windows 7 and an iPod Classic 160gb (7th gen). I managed to install Rockbox without any trouble, but after dealing with the hassles of actually using it, I decided I was better off with the native 'ware. The problem is, my uninstall efforts have stalled indefinitely because iTunes doesn't detect the iPod in DFU mode, so I can't restore it. It's not bricked, since I can still do the Rockbox foxtrot, but I still want to fix this problem.
(EDIT) I forgot to note that even though iTunes, MediaMonkey and Windows Explorer show no sign of the iPod in DFU mode, Windows itself does acknowledge it. I don't know how much this helps.
(MORE EDIT) AAaaaand now it's stuck in an infinite boot loop.
(AIN'T ALL THESE EDITS FASCINATING) Infinite loop cured, oddly by plugging it into the wall. So now we're back to the original problem.
(MEGA-CHOCOLATEY EDIT) A quick-format via Windows fixed everything!