Is Windows 10 fast startup good or bad?

When Fast Startup is enabled, your computer doesn’t perform a regular shut down. Since applying new system updates often requires a shutdown, you may not be able to apply updates and turn your computer off. Restart is unaffected, though, so it still performs a full cold shutdown and restart of your system.

Should I turn off fast startup Windows 10?

Leaving fast startup enabled shouldn’t harm anything on your PC — it’s a feature built into Windows — but there are a few reasons why you might want to nevertheless disable it. One of the major reasons is if you’re using Wake-on-LAN, which will likely have problems when your PC is shut down with fast startup enabled.