iTunes is a program that allows you to download music from its online music store, one track or a whole album at a time. iTunes also is a media player that will play all of your iTunes music and other audio files, even in other formats. iTunes can also play some video files. iTunes can rip music from CDs and burn music to CDs. It's a very versatile program that is free, even if you don't buy music from Apple. If you need to reinstall it, Apple has made it simple to do so.
To make sure that you get the best reinstallation of iTunes, completely remove the old version. Close iTunes or any other programs that are running that use any related software, like an iPod application. Go into the "Control Panel" and use the "Add/Remove programs" option. First select iTunes and click "Remove." Remove the following applications: QuickTime, Apple Software Update, Apple Mobile Device Support, Bonjour and Apple Application support. If your computer does not have all of these applications, remove the ones that are there. Restart the computer and iTunes is uninstalled.
You can reinstall iTunes if you have a copy on a disk, but Apple is constantly updating iTunes. Go to the apple website apple.com (see Resources). You will be asked for your e-mail address, but you can just click on "Download now." Download the application and install any applications that are downloaded to your computer. This will reinstall iTunes, QuickTime and any other necessary software.