If I opened iTunes and then plugged in my iPod, iTunes would freeze. If I plugged my iPod in first, iTunes would not open. I found a solution.
Close everything except Windows. Plug in your iPod. Open Task Manager (Ctl-Alt-Del). Click on the Processes tab. Close all processes that have anything to do with iPod or iTunes e.g., ipodservice.exe, AppleMobileDevice etc. It is essential that all these are closed. Close Task Manager. After a minute or so, open My Computer. Your iPod should show up as a Removable Disk. Close My Computer. Open iTunes. Your iPod should show up under Devices after about 45 seconds.