iTunes for Windows endless login loop

Hello garretg,

Let's start by making sure that iTunes is all up to date using the steps below:

Check for iTunes updates from the iTunes Download page

If you install iTunes from the iTunes Download page, you can manually check for updates to iTunes, or set iTunes to check for new versions automatically every week. 

In the iTunes app  on your PC, do one of the following:

• Manually check for new versions of iTunes: Choose Help > Check for Updates.

• Have iTunes automatically check for new versions every week: Choose Edit > Preferences, click Advanced, then make sure the “Check for new software updates automatically” is selected.

When automatic updating is turned on, iTunes checks for new updates weekly. It checks only after you have quit and restarted iTunes at least once during a seven-day period.

Check for iTunes updates from the Microsoft Store

If you install iTunes from the Microsoft Store, new versions will be automatically downloaded; however, you can manually check for updates in the Store.

• Open the Downloads and Updates pane of the Microsoft Store app.

You can also find those steps in this resource: Update iTunes on PC - Apple Support

Should that behavior still persist, you'll want to reach out to Apple Support so they can look into your particular situation further: Contact - Official Apple Support

Take care.

Repeated requests to authorize an already authorized computer for store downloads typically indicates you have corrupt or incomplete copies. Backup and then delete the tracks that won't play from your library without hiding from your purchase history. Redownload using the cloud links that should remain, or close iTunes and reopen if they don't show up straight away. While downloading click the activity widget and turn off the option that allows for simultaneous downloads.

If that hasn't helped see If iTunes for Windows prompts you to authorize your computer when you try to play purchases - Apple Support.

tt2