Did you try everything here:
Do you have iTunes version 11 installed?
Does it charge when connected?
Tried another cable?
Another USB port
Another computer to help determine if computer or iPod problem?
This usually works if it occured after installing iTunes 11
Thanks very much, but I was already in the process of another solution by the time you replied.
I updated the driver. Here's how I did it.
I right clicked on the usb icon in the bottom right thingamajig (where you click to remove flash drives etc.) When you right click, it shows Open Device and Printers. Click it.
Then it opens a window. Scroll down till you see Apple Mobile Devices USB Driver. Click it.
It the opens something else. On the top of it click Hardware.
Then click Apple Mobile Devices USB Driver in the menu.
It will open a new menu. Click Change Settings.
It will open an identical menu. Click the Driver tab on top.
Click Update Driver.
Click Search automatically for updated driver software.
It should search and install for a few moments/minutes... and you are done.
I did the following:
-plugged Ipod Touch into known working pc w/Itunes 10.6 installed & known working cable
-Apple device usb drivers are up to date
-charges when connected
-Ipod Touch trouble shooting assistant found nothing
-security software (Comodo Internet Security) does not block Itunes
- I tried everything in IOS:device not recognized in Itunes or Windows
-un-installed / re-installed Itunes components