Undo an Accidental “Don’t Trust” Computer Tap with iOS Devices
Every time you connect an iPhone, iPad, or iPod touch to a new computer, you’ll get a “Trust This Computer?” alert dialog popping up. If you’ve updated iTunes or reset an iOS device to factory settings, sometimes you’ll even see this Trust dialog box on a computer you’ve already chosen to trust from that device. Most people want to tap on “Trust”, but if you accidentally tap on “Don’t Trust” instead, the device disappears and it’s no longer accessible from iTunes on that computer, right? Wrong, you just need to trigger the dialog again so that you can trust the device.
It’s usually fairly easy to undo the “Don’t Trust” action and regain access to iOS devices, so if you find that you’ve accidentally tapped it – oops – here’s what you can do to “Trust” that computer again and be able to sync the device as intended.
1: Disconnect & Reconnect the iOS Device to Re-Trigger the Trust Computer Alert
The first thing to try is simply disconnect the device from the USB port of the computer, wait about 5-10 seconds, and re-connect it again. This should trigger the same dialog on the iPhone, iPad, or iPod touch again, and this time you can hit “Trust”.
This should work immediately, as the Trust / Don’t Trust dialog is intended to pop up every time if a computer isn’t set as trusted for that given iOS device.
Yes, use a USB / Lightning cable, as toggling Wi-Fi Sync alone is not always sufficient to bring about the trust dialog box again.
2: Reset Warning Dialogs in iTunes
If for whatever reason the USB trick didn’t work, you can reset all warnings messages and dialog alerts in iTunes with a simple trick through the app preferences, this will force the Trust dialog box amongst others to show again on the computer, not the iOS device itself , where it can then be approved again.
You should now be good to go again, and your iPhone/IPad will be accessible as intended through iTunes.
If you’re still having problems, you can try temporarily disabling the passcode lock (be sure to set one again when finished), and then update to the latest version of iTunes. Also try a different USB port and check the Devices list to confirm the connection is active, sometimes it’s just a matter of a faulty USB port or connection.