Try rebooting it, but make sure that you have no internet access at all when you do. Sometimes, when Windows 10 updates/installs it gets stuck. Unlike in prior versions if something it was installing didn't take/work, it would move past it and just tell you it didn't install. 10 doesn't seem to do that. It just gets stuck trying over and over. Serious flaw in my opinion.
So, make sure your device has absolutely no way to connect to the internet and then reboot it. It should load up and then you can reconnect to the internet.