How to Turn Fast Startup On or Off in Windows (and When You Actually Should)

You want to turn Fast Startup off (it’s causing odd shutdown behavior) or back on (you want quicker boots) in Windows.

Why: Fast Startup makes the PC boot faster after shutdown by hibernating the kernel session to the hiberfil.sys file instead of fully closing it. That’s normally fine — but it can cause a shutdown to fail and bounce back to the lock screen, and a plain “Shut down” no longer gives you a truly fresh boot. (Note: Fast Startup is enabled by default, and Microsoft does not recommend disabling it unless you have a specific reason.)

Fix 1: Turn Fast Startup off (or back on) in Control Panel

1. Open Control Panel > Power Options > Choose what the power buttons do.
2. Click Change settings that are currently unavailable (this unlocks the greyed-out boxes).
3. Under Shutdown settings, untick Turn on fast startup (recommended) to disable it — or tick it to re-enable.
4. Click Save changes and reboot.

Fix 2: If “Turn on fast startup” is missing from that screen

The checkbox only appears when hibernate is enabled, because Fast Startup relies on the hibernate file. Enable hibernate in admin Command Prompt, then return to Fix 1:

powercfg /hibernate on

If you instead want Fast Startup gone entirely, disabling hibernate removes it (this also deletes hiberfil.sys and frees the space):

powercfg /hibernate off

With hibernate off, both Hibernate and Fast Startup are unavailable, while normal Sleep and Shutdown keep working.

Fix 3: Force a true full shutdown without changing the setting

If you just need one genuinely fresh boot (for example to clear a hardware glitch) without turning Fast Startup off permanently, use Shutdown.exe, which performs a full shutdown by default:

Shutdown /s /t 0

A normal Restart also always does a full boot cycle — Fast Startup never applies to Restart — so restarting is another way to get a clean state.

FAQ

Will turning off Fast Startup break anything? No. Your PC just takes a little longer to boot. Sleep, Hibernate (if enabled), and Shutdown all keep working.

Why does “Shut down” not fully restart drivers but “Restart” does? With Fast Startup on, Shut down half-hibernates the kernel; Restart performs a complete boot cycle. That’s why “Did you try restarting?” sometimes fixes what a shutdown didn’t.

Shutting down sometimes fails and returns to the lock screen. Microsoft attributes this to Fast Startup in some cases — turn it off (Fix 1) or use a full shutdown (Fix 3) as a workaround.

Sources: Microsoft Learn — Fast startup causes hibernation or shutdown to fail, Microsoft Learn — How to disable and re-enable hibernation