Computer doesn't recognize ipod

Somebody please help!!! My ipod nano is no longer being recognized by my computer, itunes, and it will not charge my ipod. The error that pops up from my computer is..."One of the USB devices attached to this computer has malfunctioned, and Windows does not recognize it." When I click the error it shows me a screen that shows that the item connected is an unknown device. I don't know what to do. It never did this before, my pc and itunes recognized it previously. I think part of the problem is that my co-worker knew that my ipod was dead and I needed to commute home from work and she plugged it into a charger that was not made for Ipods. She told me that her charger wasn't charging it and it would only make the screen light up. That is the only thing that happen that was different. If anyone has an answer to fix this it would be fantastic!!!!!!!