Also, when iTunes greets you with a Welcome to Your New iPhone screen, select Set up as new iPhone and click on the Continue button.

If you’re connecting your iPhone/iPad first time with iTunes, you’ll get a “Do you want to allow this computer.” pop-up on screen, select Continue.

Get the iOS 12 IPSW firmware file for your device from the link above and follow the instructions below to flash the firmware via iTunes.

You can download iOS 12 IPSW firmware for your iPhone or iPad model and update your device manually using iTunes.

How to Update to iOS 12 manually using IPSW firmware If asked, enter your passcode on your iPhone to let iTunes download and install iOS 12 on your device.Click on Download and Update button when iTunes detects the iOS 12 update.Once your device is shown on the iTunes screen, click on the Check for Update button.

Also, when iTunes greets you with a Welcome to Your New iPhone screen, choose Set up as new iPhone and click on the Continue button. If a Trust This Computer pop-up shows on your device’ screen, make sure to click on Trust.Connect your iPhone/iPad to the PC using the original USB cable that came with your device.Open iTunes on your Mac or Windows PC.However, if you’re unable to install iOS 12 OTA update, consider upgrading your iPhone to iOS 12 via iTunes on your computer. Installing the iOS 12 update over-the-air is the simplest method to update to iOS 12. Let your iPhone check for available updates, and tap Download and Install when your device detects the iOS 12 update.How to update to iOS 12 manually using IPSW firmware.Here are some easy to follow guides to update to iOS 12 directly from your iPhone OR via iTunes OR by manually downloading the iOS 12 IPSW firmware file. The update will be available to download over-the-air through your iPhone’s Software Update section OR from iTunes on your computer. Apple will today start rolling out the much-awaited iOS 12 update for everyone to install on their supported iPhone and iPad devices.

Itunes check for updates