Hey there k8ei,
Thank you for using Apple Support Communities
I found this article for you to help troubleshoot installing iTunes named Trouble installing iTunes or QuickTime for Windows found here http://support.apple.com/kb/HT1926.
Here is a general overview on where the troubleshooting will take you:
General installation troubleshooting
After performing each of the steps below, you will need to completely remove iTunes and related components and then install iTunes again to determine whether the issue is resolved.
All the very best,