Once you restart your computer (if you had to restart it), open i Tunes again.
What Apple fails to mention is that the update break Yellosn0w, the hack which unlocks the i Phone from the official carrier and lets you slip in any SIM card.If a new i OS update is available, you should have already clicked "Update".You'll see a pop-up message from i Tunes, notifying you that it is about to update your i Phone's software and that it will verify the update with Apple.The phone's name (which you gave it when you activated it) will appear under the "Devices" heading in the menu that runs on the left side of the i Tunes screen.i Tunes may begin backing up and syncing your i Phone automatically, depending on whether or not you've set it to sync automatically.If you haven't set up automatic syncing, you can do it manually. Double click on the i Phone icon in the menu on the left side of the i Tunes screen to open the i Phone Summary screen.Apple delivers its i Phone software updates through i Tunes, so the first thing you should do is make sure you have the most recent version of i Tunes running on your computer.To update i Tunes, go to the "Help" menu, and select "Check for updates."If i Tunes says you have the most recent version, you're all set to move on to Step Two.Let this run; do not disconnect your i Phone while it is doing so.When the update process is complete, i Tunes may not give you any notification.If you see a button that says "Check for Update," that means i Tunes has not automatically found a newer version of the i OS software.Click this to manually check for an update; if your i Phone is already running the most current version, you'll see a pop up message saying "This version of i OS (x.x.x)* is the current version." That means no updated software is available.* = version of the software.