iTunes 7 or later for Windows Installation stops responding while "registering modules"
Symptoms
Some customers may experience an issue when trying to install iTunes 7 or later for Windows where the installer will freeze while "registering modules" as shown below:

Products Affected
iTunes 7 for Windows, iTunes 8 for Windows, SpyCatcher
Resolution
This symptom may be caused by anti-spyware software preventing iTunes from installing correctly. One such application is SpyCatcher. Before installing iTunes, temporarily remove this software to allow the iTunes installer to complete.
Important: Information about products not manufactured by Apple is provided for information purposes only and does not constitute Apple’s recommendation or endorsement. Please contact the vendor for additional information.