How do I hard reset an iPad Air 2

There is nothing called a "hard reset" with iOS devices.

Forced restart: press and hold the Home and power buttons until the apple appears, then allow to continue starting. No data is lost

Erase all content and settings: Settings>General>Reset>Erase all content and settings. This will delete all persona information on the device but will not update the iOS. If the phone is activation locked, the Apple ID password will be required.

Restore: use iTunes. Everything will be wiped. You can reload a back up or restore as new. If the phone is activation locked, the Apple ID passcode will be required.

If you're asking if there's a way around the Activation Lock, the answer is no.

I had similar problem, but that after I bought my new IPhone 7 and updated my account, I have 3 diveces iPhone s5, iPad Air2 and iPhone 7. Now after I update account I couldn't run my iPad anymore, I tried restart both my new iPhone7 and iPad, but still can't run my iPad as the image attached. Please can you help.

Thank you

Hi. Here are the Apple instructions If you can't update or restore your iPhone, iPad, or iPod touch - Apple Support.

You are in recovery mode. You need to restore it through iTunes on your computer then reload your most recent backup.

Sorry but I never do that, do you have a link to guide me with more steps detailed will be more thankful