1. Click the 'Start' button on your PC's desktop, and click 'Control Panel' from the pop-up menu.
2. Select the 'Add or Remove Programs' link in the Control Panel window in Windows XP, or select the 'Uninstall a program' link underneath the 'Programs' section of the Control Panel window in Windows 7 or Vista.

3. Select 'iTunes' in the Add or Remove Programs window, and click the 'Remove' button. Repeat this step for 'Bonjour,' 'QuickTime' and 'Apple Mobile Device' in the Add or Remove Programs window. For Windows 7 or Vista, select the program you wish to remove and click the 'Uninstall' button at the top of the program window.
4. Go to the Apple website (see Resources). Select the 'iTunes' tab, and click the 'Free Download' button.
5. Enter your email address, and click the 'Download Now' button. Click the 'Run' button on the pop-up box, and click the 'Run' button in the Security Warning window.
6. Click 'Next' in the iTunes QuickTime Installer window, and follow the on-screen installation instructions to complete the reinstallation.