How to Authorize a Computer with iTunes

If you have a new computer, you’re going to want to authorize it with iTunes and an Apple ID. Authorizing iTunes does quite a bit, it lets you sync apps, books, music, movies, and other content from the iTunes Store, re-download past apps from the App Store, it enables Home Sharing with iTunes, and also allows for some iCloud specific features like Automatic Downloads. In other words it’s basically essential, and it’s very easy to do, make sure you have have an active Apple ID before continuing:
- Launch iTunes on the new computer (PC or Mac)
- Pull down the “Store” menu and select “Authorize This Computer”
- Enter your Apple ID and password at the next screen and click on “Authorize”
You can authorize up to five personal computers of any variety of Macs or Windows PC’s. In other words, up to five computers can sync and share your data and purchases. If you go over that number, you’ll need to deauthorize one of the computers before authorizing a new one.

Is there any limitation for the number of iDevices, e.g how many Ipad, Iphone can be attached to an AppleID?
Authorizing happens nearly automatically. I would really value a how-to for deauthorizing old computers after they have been thrown away years ago.
@Jon
Me too!
Just go to “unauthorize computer” option.
Then you have the choice to unauthorize ALL computers attached to your Apple account.
Then you can authorize one by one the computers you want.
This can be done only once a year.
[...] connect the iPhone to the new Mac, launch iTunes, confirm that everything is in order, and authorize the new [...]
my iTune doesn’t have the browser. I don’t know where Store Menu is.