Q: Hint on Deauthorize All on iTunes 12

As usual, Apple's help page (deauthorize all computers) is awful, but I figured out how to find the Deauthorize All button, so I figured I'd pass it on and hope those who search for how to do it will find this post.

1. Launch iTunes 12 (have not tried Windows version, FYI).
2. Under Store menu, select View Account (you may need to sign in first).
3. Click View Account button.
4. You should see the Deauthorize All button at the bottom of the first section ("Apple ID Summary"). It will only appear if you have more than 1 authorized device.

I hope that helps.