Use this tip at your own risk. If it works on my PC, it can work on yours.
For the ones having that iTunes problem, which iTunes recognizes the iPod but doesn't sync and shows the message "iPod cannot be synced. Required disk cannot be found" or ""The iPod could not be restored. An unknown error occurred (1418)", here's my advice:
1 - Read the Apple Troubleshooting article available at
http://docs.info.apple.com/article.html?artnum=304996. Try every solutions, even the one saying "Try deleting or removing any third-party Windows OS skins, Windows themes, or desktop mods that are installed(...)". Yes, you should uninstall VistaMizer. He's the one who messed up your computer.
2 - Still not working? Try reinstalling your iTunes, but backup your library first.
3 - And finally, the solution which really worked well. Disconnect your iPod, close iTunes. Remove the iPod from the dock, open "My Computer" and leave the window on a visible spot. Place the iPod on the dock. Check if any new removable drives appear. If it does, keep reading. If not, then I'm afraid I can't help you. Now that we can see the iPod drive, open iTunes. [POINT OF RESTART] Put the new songs you want, as much as you want, or delete the old ones, do something that trigger the automatic syncing by iTunes. The software will try to sync, and it probably will show the same problem as before. Don't panic, everything is fine, don't use CTRL
ALTDEL, please. Just close the window displaying the odd message when it appears. Leave iTunes open, displaying your iPod content. Go back to the "My Computer" window. Leave it on a visible spot. Now let's start the magic, go to "Start" -> "Control Panel" -> "Add New Hardware". Click on "Next". You will see your iPod drive reappearing on the "My Computer" window. Just return to the iTunes window, click on "File", "Sync iPod" and it's done. After syncing, the iPod drive will disappear from the "My Computer" window. To sync again, repeat the operation from the point of restart. To eject your iPod, do it as you would do on a normal operation.
That is just a trick, but it works perfectly while Apple doesn't release a bug fix. Forcing the detection of the iPod drive was the only solution that I found after hours trying to make my brand new iPod Shuffle work. Sorry for any misunderstandings caused by bad english.
Solution by Renato Caggiano Concilio
*Keep the credits, please!*