Arnie gets constant updates on Windows 10, but the last one won't let him shut down the computer. It starts to shut down, the screen goes black, but the computer won't turn off. Leo says it's a failure of Windows update, where it stops the shut down process until all programs are closed out. Many services are running in the background and they have to shut down before the computer turns off. If there's a bad process that won't stop, it causes the computer to stay on, crashing the computer. It's very common. To diagnose it, Arnie should look in Task Manager and see what's running. He should close down each task and try to shut down. That will indicate what program needs repair or a reinstall.
Process Explorer is free from SysInternals at Microsoft. That is more powerful and will let him know what's running. Another issue is something called "fast startup." He should disable that. He can right click Start, then click Power Options. He should look for "Change settings that are currently unavailable", and uncheck Fast Startup. That could fix it.