Q: my iPhone 4s just got upgraded to iOS 9 it won't turn back on now?

Greetings kudratkash,

Thanks for the question. If I understand correctly, you are stuck on the Slide to Upgrade screen. I would recommend that you read this article, it may be able to help the issue.

If your iOS 9 device is stuck on Slide to Upgrade - Apple Support

Thanks for using Apple Support Communities.
Take care