Q: itunes install freezes at 'unregistering itunes automation server'

Well hello there, hallielouise28!

Welcome to the Apple Support Communities. Having an up to date and functional iTunes library is certainly a must! Together, we'll get to the bottom of this and have you listening to your tunes in no time. 

If you can, the first suggestion is to create a backup of your iTunes media folder. Find those steps here: 

Manage and back up your iTunes media library

Now that we have that out of the way, your specific situation might require a full uninstall of iTunes. This article highlights the very specific order in which we remove the different components of iTunes. Aside from removing just the program, we'd like to remove other items, such as the "Apple Software Update". This article will walk you through it all: 

Remove and reinstall iTunes and related software components for Windows 7 and later

Cheers!

Welcome back hallielouise28, 

We're sorry to hear that the iTunes software is still appearing to cause this error when installing. After removing all related components of iTunes, and completing a fresh install, we will start to look at the Windows platform. With a Mac computer, the next item we would complete is called a "Safe Mode" boot. Here are similar steps for a Windows computer. Give this a try. If further assistance is required, it'd be most beneficial to contact Microsoft and confirm that there are no third party applications or software snags that may be causing this error to populate. 

How to perform a clean boot in Windows

Have an amazing day!