Unable to Install Update; An error occurred installing iOS 8.2

I have an iPhone 6 128 GB which is not jailbroken. The current version of iOS on the phone is 8.1.3 and yesterday I wanted to update to iOS 8.2. The download went through without any problem but while installing, it gave the error:

Unable to Install Update
An error occurred installing iOS 8.2

Tried installing after switching Off and ON and also tried Hard Reset (Holding Home button and On/off switch). Same error displays every time.

Also the Touch ID has stopped working and I find that the Settings - Touch ID & Passcode - iPhone Unlock is OFF. When I try to switch it ON, the system displays the error

Failed
Unable to complete Touch ID setup. Please go back and try again.

Is anyone facing this problem? I live in India.


Power off the phone, and hold down the power button and home button at the same time until the device powers on. At that time, release the power button, but continue to hold the home button, which should start your phone in recovery mode and show an iTunes/USB Plug icon on the screen, which indicates for you to plug it into your computer with the USB data cable (computer with iTunes installed on it and open.)

Once you plug in the USB data cable to your phone/computer with iTunes, it should detect a phone (your phone) in recovery mode, and you should be able to fully recover your phone by restoring the latest iOS version to it.