This wikiHow teaches you how to tell iPhone that the computer you're connecting to can be trusted with iPhone data. This method is also required to sync iPhone with computer.
Step
Part 1 of 2: Trusting Computers
Step 1. Connect your iPhone to the computer via USB
You will be asked to trust a computer that you have never connected and trusted before.
Step 2. Open the iPhone screen
The screen will need to be opened to trust the computer you are connecting to.
Step 3. Tap Trust on the notification that appears
You should see this notification appear as soon as you open the screen.
If the Trust notification doesn't appear, you may have trusted this computer before. If not, you may need to reset the Trust settings
Step 4. Tap Continue in iTunes (if prompted)
Depending on your computer settings, you may see this notification appear after tapping Trust. This will launch iTunes on the computer.
Part 2 of 2: Reset Trust Settings
Step 1. Open iPhone Settings
You can find the Settings app on the Home screen. The icon is a gray gear.
Step 2. Tap General
You'll find this at the top of the third group of options.
Step 3. Scroll down and tap Reset
Step 4. Tap Reset Location & Privacy
Step 5. Enter your passcode if prompted
Any computers you previously trusted will be deleted from iPhone memory and you'll be prompted to trust all computers you connect to.
Step 6. Reconnect your iPhone to the computer
The Trust notification should appear after unlocking the screen.
Step 7. Check for iTunes updates
If the Trust notification doesn't appear, iTunes may be outdated and can't connect. You can check for updates using the iTunes update checker.
Step 8. Restart your iPhone
Restarting your iPhone may bring up a notification. Press and hold the Power and Main Menu buttons until the screen fades and the Apple logo appears. Try connecting one more time after the iPhone turns on.
