Q: restore IPad2

Can you describe the issue in more detailed way?

How to erase your iOS device and then set it up as a new device or restore it from backups - Apple Support

iPad 2s are one of the primary victims of the "activation server" problems that Apple knows they have.

The solution is to wait for Apple to find and fix the problem, which will likely present itself unceremoniously as merely success the next time you try

EDITadded

I have read that you can take your iPad to the Apple Store with proof of ownership docs and they will fix it - no reports back to these threads of success or failure