Q: Stuck on connect to itunes and gives error 29

Did you already try these steps?

Here's what to check:

1. If iTunes is already open, quit and reopen it.
2. Make sure that you have the latest version of iTunes.
3. Check for issues with third-party security software.
4. Make sure that your USB cable, computer, and network are reliable. Then try twice more to restore your iPhone, iPad, or iPod.
5. If you still see the error message, you can check for outdated or modified software or contact Apple Support.

copied from: Get help with iOS update and restore errors