Hi John,
Go into Programs and Features and uninstall in this order:
iTunes
Apple Software Update
Apple Mobile Device Support
Bonjour
Apple Application Support
Reboot. Download a new copy of iTunes. Right click on the exe file and select Run as Administrator.
We experienced the same problem.
If the driver 'rolls back' when you try to delete the Apple Mobile Device Support app from Uninstall Programs, go to the Services in Device Manager and select Repair.
You may have to do this a couple of times. Then go back to delete the Apple Mobile Device Support app.
After a couple of attempts repairing the service the Apple Mobile Device Support app deletes.
Once you have all the apps listed above deleted, download a new copy of iTunes and install. From there it will be clear sailing and all will be back to normal.
mr martin