Why wont iTunes recognize my iPod?

Ok. I have a really old U2 iPod (http://gizmodo.com/024238/black-ipod-u2-edition) that is in perfect condition. I just got a new hp computer and put iTunes on it but when I plug in my iPod it wont recognize it. A thing pops up and says that it's a foreign device. I'm kind of electronically challenged and I really don't want to mess up my computer or iPod.