IPOD NOT RECOGNIZED, HELP!!!

For some reason everytime I plug in my ipod mini 3rd generation into my computer, it's no longer recognized by my computer or itunes. It's never happened to my before, so I have no idea what to do! I have the latest version of itunes and i've tried reseting my ipod and restarting my computer but nothing works. Everytime I plug in my ipod a window pops up the "Found New Hardware Wizard" and when i do that, another window pops up that says that I need to insert the Windows XP Professional Service Pack 3 CD-ROM, which I don't have...and it's never showed before. Can anyone help???