"Stuck on slide to upgrade" backup taking forever

Hi after updating to IOS9, my iphone 5s is facing the "slide to update" problem. I tried to follow the steps to back up my phone using itunes. The back up is taking forever! I have left it for 5 hours and there is no progress. It is only showing "Backing up iphone..." and the blue status is running and not showing any progress.

Please help!

Thanks