authorization after deauthorization

Deauthorization

You can de-authorize individual computers, but only by using those computers. Your other option is to "de-authorize all" from your iTunes account.

1. Open iTunes on a computer
2. From the Store menu, select "View my Account..."
3. Sign in with your Apple ID and password.
4. Under "Computer Authorizations" select "De-authorize All".
5. Authorize each computer you still have, as you may require.

You may only do this once per year.

• After you "de-authorize all" your authorized computers, you may re-authorize each one as required.
• If you have de-authorized all computers and need to do it again, but your year has not elapsed, then contact: Apple - Support - iTunes - Contact Us.
• For more information on authorization and de-authorization: iTunes Store- Authorize or deauthorize your Mac or PC.

Authorization

iTunes Store - Authorize or deauthorize your Mac or PC.

In iTunes you use the Authorize This Computer or De-authorize This Computer option under the Store menu in iTunes' menubar. For Windows use the ALT-S keys to access it. Or turn on Windows 7 and 8 iTunes menus: iTunes- Turning on iTunes menus in Windows 8 and 7.

Have you tried signing out of iTunes and back, then trying again?

If necessary, contact iTunes Support. Either use the form or scroll to the bottom of the page in the 2nd link. Follow through the screens to get a chat or telephone option.  You may need to pick a problem that is slightly different than yours to get a chat option.  

iTunes Support

iTunes Support – world wide