i was trying to update my 2nd generation ipod to 4.02 and then it stoppes and said it needed the software that came with. i was going to restore my ipod to see if that would solve the problem but it wont even show up on itunes anymore
1) Restart the iPod Service
2) Remove and reinstall iTunes
3) Empty your Temp directory and restart
4) Disable conflicting System Services and Startup Items
5) Update, Reconfigure, Disable, or Remove Security Software
6) Delete damaged or incorrect registry keys
[iPod appears in Windows but not in iTunes|http://support.apple.com/kb/TS1363?viewlocale=en_US] should fix the problem or at least give you specific errors we can look at further if need be. But you really need to try all of those first, including the links that are XP specific.
Be sure you turn off all antivirus, spyware, etc. (#5) and try a different USB port as you troubleshoot.
If you have tried all this and it still is not recognized in iTunes, try the steps in [Unable to Update or Restore|http://support.apple.com/kb/HT1808]. You will lose all your data but hopefully that will solve your problem if the other steps don't work.
You could try plugging it into a different computer but if it stopped during an update I suspect you will still need to restore it. It's kind of hard to know since with the info you've provided I'm not sure if the issue is with your ipod or something on your machine.
It wouldn't hurt to try it with another machine and see if it works. Sometimes you don't really know with these things until you just try and see what error messages (if any) you get.
