My laptop reads all my iPods as corrupted...

I have reset the iPods numerous times but I keep getting the error message, "iTunes has detected an iPod that appears to be corrupted. You may need to restore this iPod before it can be used with iTunes. You mat also try disconnecting and reconnecting the iPod." I know the iPods ( a Classic 160GB and a Nano) are not corrupted because they work in my office. I have deleted and reinstalled all the iTunes applications (as stated in the Apple tutorials). I have a Dell Vostro 1500 laptop running Windows XP. Any idea what may be the problem?