iTunes for Windows, QuickTime, and Apple Application Support

*The relationship between iTunes for Windows and QuickTime for Windows*

Conceptually, you don't go too far wrong thinking of iTunes for Windows as a gigantic QuickTime for Windows plug-in. QuickTime for Windows provides the audio and video playback capabilities for iTunes for Windows, the codecs iTunes for Windows uses for importing and burning CDs, and so forth.

So, under normal circumstances, if you uninstall your QuickTime for Windows your iTunes for Windows will no longer launch. The exception is if you install a different application such as QuickTime Alternaltive, which also provides QuickTime playback capabilities. However, most such applications (QuickTime Alternative being a good example) are themselves built from actual QuickTime program files. So there's really no getting away from the requirement to have QuickTime for Windows componentry installed on your computer in order to get your iTunes for Windows to launch and run.

In addition to needing some QuickTime for Windows installed on the computer for iTunes for Windows, a given iTunes for Windows version will require *at mininum a particular version* of QuickTime for Windows to be installed on the computer in order for that iTunes for Windows version to run. For example, iTunes for Windows 5.0.0.35 requires at least a release version of QuickTime for Windows 7.0.2 to run correctly, iTunes for Windows 6.0.0.18 requires at least a QuickTime for Windows 7.0.3, and so on. The same applies for solutions involving other programs like QuickTime Alternative. An iTunes for Windows 6.0.0.18 would require an installed version of QuickTime Alternative to made from (at least) QuickTime for Windows 7.0.3 componentry in order for iTunes to run.

The most straightforward way to go about getting your iTunes for Windows launching again after you've uninstalled your QuickTime for Windows is simply to reinstall QuickTime for Windows. You can get the latest version of QuickTime for Windows XP, Windows Vista and Windows 7 from the following download page at the Apple website. (Use the download link that doesn't mention iTunes.)

[Latest QuickTime for Windows version|http://www.apple.com/quicktime/download>

*The relationship between iTunes and Apple Application Support*

iTunes for Windows uses a number of the same program files as other Apple software for Windows (most notably, QuickTime for Windows and Safari for Windows). Starting with iTunes for Windows version 9.0.0, QuickTime for Windows version 7.6.4, and Safari for Windows 4.0.4, program files common to more than one of the programs have been stored in a single location: "Apple Application Support".

So, if you uninstall your Apple Application Support (using the Add or Remove programs control panel in Windows XP, or using Programs and Features in Windows Vista or Windows 7), your iTunes for Windows 9.0.0 (or higher version) will no longer launch ... because several essential program files for iTunes for Windows 9.0.0 (or higher version) will have been uninstalled.

At the time of writing this user tip, Apple Application Support is not available as a "standalone" download from Apple. It is only available as part of the installer bundles for the most recent versions of iTunes for Windows, Safari for Windows and QuickTime for Windows. So if you have uninstalled your Apple Application Support and your iTunes for Windows 9.0.0 (or higher version) is no longer launching, the most straightforward way of getting your iTunes for Windows launching again is to uninstall your existing version of iTunes for Windows and reinstall the latest version of iTunes for Windows. (The iTunes reinstall should also reinstall your Apple Application Support.)

[Latest iTunes for Windows version|http://www.apple.com/itunes/download>

If, however, you've uninstalled both your Apple Application Support and your QuickTime for Windows, the most straightforward way of getting them both reinstalled is to download the latest QuickTime for Windows installer from the Apple website. (Use the download link that doesn't mention iTunes.)

[Latest QuickTime for Windows version|http://www.apple.com/quicktime/download>

This is the 1st version of this tip. It was submitted on March 7, 2010 by b noir.