It sounds as though you need the cleanup utility.
Unfortunately the Microsoft Installer Cleanup utility has been withdrawn by Microsoft because of compatibility issues with Microsoft Office so you will need to find a copy elsewhere – the installer ismsicuu2.exe. You need version 3.
Google msicuu2.exe download
mydigitallife in the above search has a copy of version 3
Checkfor malware before installing it.
After installing, To run the program – All Programs>>Windows Install
If you get permission denied error, Try Run as Administrator – an option if you right click on the program.
Before using the utility I would try to uninstall all the components of iTunes using the following method:
Any program that will not uninstall will need cleanup - it may be just iTunes.
When you run the utility, look for iTunes and remove it. Do the same if any of the other programs will not uninstall.