Hi there davidlx!
I have some information for you that should be able to help you get iTunes updated on your PC. The first article I would like you to look at is about using Software Update for Windows to update iTunes, and it can be found here:
Using Software Update for Windows to keep your Apple software up-to-date
http://support.apple.com/kb/HT2305
Another way to update your iTunes software would be to uninstall iTunes from your PC, then download the latest version of the software. iTunes requires that the programs involved with iTunes be uninstalled in a specific order, more information on which can be found here:
Removing and Reinstalling iTunes, QuickTime, and other software components for Windows XP
http://support.apple.com/kb/HT1925
And you can find the latest version of iTunes available for download here:
Apple - iTunes - Download iTunes Now
http://www.apple.com/itunes/download/
Thanks for using the Apple Support Communities. Have a good one!
-Braden