Q: my desktop wont authorize with itunes

Greetings peanut meamaw,

Thanks for the question. If I understand correctly, you are trying to authorize another computer, but it says you are at the max number of authorized computers. I would recommend that you read this article, it may be able to help the issue.

Deauthorize your computer using iTunes - Apple Support

See how many computers you've authorized

Click to open iTunes and sign in to your Account Information, or use the steps below:

1. Open iTunes.
2. Click Sign In and enter your Apple ID.
   
3. Click your name, and select Account Info from the drop-down menu.
   
4. Enter your password again.

In the Apple ID Summary section, next to Computer Authorizations, you’ll see the number of computers that you’ve authorized. You won't see the names of those computers. 

If your computer doesn't work or you don't have it, you need to deauthorize all computers and then reauthorize the ones you're still using.

Thanks for using Apple Support Communities.
Take care