I have been having the same problem:
I have an ipod with color display. I've had it since October. I use it on my laptop and my desktop. It has always worked fine and there's been no problem with it until last night.
It was plugged into my laptop and the screen on the ipod had the "Do not disconnect" symbol. I was doing something else, but noticed the screen light up and change to the normal beginning menu screen. Then the bubble in my taskbar popped up and said, "USB Device not recognized."
So I unplugged it from my laptop and moved it over to my desktop. When I plugged it in, the same bubble appeared.
Since then, I've reset all the settings on my ipod. I also uninstalled and re-installed the newest versions of itunes and ipod updater. I also got the latest service pack from Microsoft. Restarted the computer and tried again. Nothing.
In the device manager, it reads as an "Unknown Device" and the device status reads "No drivers are installed for this device". I tried to automatically update the drivers, but windows says it has the best driver.
I, too, no longer have the installation cd that came with my purchase. Everywhere that offers a driver just downloads the ipod Updater. Since none of the programs (Windows, itunes, Updater) recognize there is an ipod connected, none will work.
Any suggestions? Is there any way to get only the driver without the updater? Am I just out of luck?