I am trying to authorize my computer on Itunes, but there is no option

The option for authorizing will be found under the Accounts menu of iTunes.

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 or Accounts 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.

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.

Repeated requests to authorize an already authorized computer for recent store downloads typically indicates you have corrupt or incomplete copies. 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 prompts you to authorize your computer when you try to play iTunes Store purchases - Apple Support.

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