I am unable to update my iTunes. When I try, I get a message saying needed files are on a resource that is unavailable. How can I remove my current iTunes and reinstall it?

Hi, I have an iPod Touch 5th generation.

I have a Windows XP computer.

I cannot update my version of iTunes.When I try, I get a message saying that the needed files are on a network resource that is not available.

This has happened before, but has been fixable, but.not by me..

Can I fix it myself? if so, how? I'd like to uninstall iTunes and reinstall it so I can update it.

thanks for any help. nanc3