Those who tried to update their Apple devices via OTA (Over-The-Air) were the most affected. However, there were no reports about those who updated the firmware manually via iTunes.
After coming to know about the problem, Apple tried examined the issue from its end and has fixed it. It is said that OTA update attempts to download iOS 10.0, while the iTunes updates to iOS 10.0.1, resulting in the devices going into boot-loop.
The company has accepted that some users were affected, however, the problem was resolved. According to Apple, those who were affected should connect to iTunes to complete the update instead of iOS 10 installation via OTA.
And if you are clueless about how to upgrade your Apple device manually through iTunes on PC, here is how you can do it.
1. Use the latest version of iTunes.
2. Connect your device to your computer and open iTunes. If you face any problem, go to either Apple Retail Store or Apple Authorized Service Provider for help.
3. Force-restart your device while remain connected: Press and hold both the Home and Sleep/Wake buttons for a few seconds until you see the Apple logo. Release the button only when you see the recovery mode screen.
4. Choose update when you see restore and update options: iTunes will reinstall iOS without erasing your data. Wait till iTunes downloads the software. If it takes more than 15 minutes, you will have to repeat these steps and choose Restore instead of Update.
5. Set up your device after the Update or Restore gets done: Fill in name, Apple ID, date and time and other details. If you have previously backed up your device with iTunes, you might be able to restore from your back-up during set-up.