Q: computer doesn't reconize my IPod.  How can this be fixed?

If the computer (not just iTunes) is not seeing the iPod at all, try a different USB docking cable to rule out faulty cable as the cause, OR use your current cable with another device to confirm it is good.

If the computer does see the iPod as a connected USB device, try this procedure to restart the Apple Mobile Device Service

Restart the Apple Mobile Device Service (AMDS) on Windows - Apple Support

If that does not help, you may want to completely remove iTunes and related software components.  This Apple document lists all components of an iTunes installation, and the precise order to uninstall them

Remove and reinstall iTunes and related software components for Windows 7 and later - Apple Support

Then download and install the latest version of iTunes

http://www.apple.com/itunes/