Q: Why does Itunes not uninstall properly?

Because of the way that Windows uninstalls iTunes. Many programs when using the uninstall utility in Windows leave traces of things behind. That is why Apple provides a support document to give users the information on how to uninstall all traces of iTunes and Apple Software prior to an reinstall attempts. This is the support document if you do not have it. Remove and reinstall iTunes and related software components for Windows 7 and later - Apple Support

The iTunes setup file contains multiple installers and an additional file that manages the installation. iTunes needs all of the supporting components to work properly. The registered installer for each component, of which iTunes is one, is only able to uninstall or repair itself. It is possible in principle to write a batch file to remove all components in succession, though it may require knowing which version of iTunes you are trying to uninstall, or the location of the .msi files that were used to install it.

Should you want advice on repairing an iTunes installation see Troubleshooting issues with iTunes for Windows updates.

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