unknown error occurred (0xE8000015)

Hello apphole5150,

Welcome to Apple Support Communities!

If we understand your post correctly, you're getting the message that an error occurred when trying to restore your iPhone 7. We'd like to provide you with help.

Take a look at the steps below to see if it helps, from the article: If iTunes doesn‘t recognize your iPhone, iPad, or iPod

"If your computer doesn’t recognise your connected device, you might see an unknown error or a “0xE” error. Follow these steps and try to connect your device again after each step.

1. Make sure your iOS or iPadOS device is turned on, unlocked and on the Home screen.
2. Check you have the latest software on your Mac or Windows PC. If you’re using iTunes, make sure you have the latest version.
3. If you see a Trust this Computer alert, unlock your device and tap Trust. If you can’t unlock your device because you forgot your passcode, find out what to do.
4. Unplug all USB accessories from your computer except for your device. Try each USB port to see if one works. Then try a different Apple USB cable.*
5. Restart your computer. 
6. Restart your iPhone, iPad or iPod touch.
7. Follow these additional steps for your Mac or Windows PC. 
8. Try connecting your device to another computer. If you have the same issue on another computer, contact Apple Support."

Let us know if you have any questions.

Thank you for using Apple Support Communities.

Take care!