Windows’ Fast Startup is one of the best examples of a disruptive setting. It’s enabled by default and was the cause of my Linux partition not mounting, my dock randomly disconnecting, and an update getting stuck in a loop. Disabling it had no real noticeable impact on startup times, but it fixed all three seemingly unrelated issues. It’s time to start paying attention to this setting.
Fast Startup isn’t a full shutdown
I expected Windows to boot much slower
When I decided to turn off Windows’ Fast Startup, I anticipated my boot times would be six to ten seconds longer, and I convinced myself that it would be a trade-off I could live with.
I couldn’t have been farther from the truth. Shutdown-to-desktop time increased by only about two seconds (roughly 11s to 13s); without a stopwatch, the difference would be imperceptible.
It only started to make sense as I began understanding what Fast Startup really does. When enabled, a shutdown doesn’t close everything in Windows. Despite your session logging off as it normally should, kernel sessions do not completely shut down; Windows saves the kernel state and loaded drivers to the hiberfil.sys file. When you turn on your system the next time, Windows boots back from the saved kernel session. What you get is a shortcut rather than building the system startup from scratch.
There was a time when this setting served an important purpose. On an NVMe SSD, the difference is minor; on a mechanical HDD, where reads/writes are slower, the impact can be significant.
|
Action |
Fast Startup enabled |
Fast Startup disabled |
|---|---|---|
|
Shut down |
Hybrid shutdown (kernel session saved) |
Full shutdown |
|
Restart |
Full restart |
Full restart |
|
Driver initialization |
Restores previous kernel session |
Loads fresh kernel session |
However, what really surprised me wasn’t boot time, but what happened when my computer was fully operational.
Three problems shared the same cause
The fix depended on Windows starting with a completely fresh kernel
Even though these problems had existed for months, they seemed to affect separate components and felt very unrelated. But all three disappeared once I disabled that one setting.
Let’s start with my USB dock. I noticed that a few times a week, when I turned on my computer, my external drive or monitor might not show up. The only way I could get it to work was to disconnect and reconnect the dock. Fast Startup causes Windows to reuse driver states rather than fully re-initializing them, which can prevent some devices from resetting, matching the behavior I observed.
The second problem was even more serious. I have a dual-boot setup that includes a Linux partition. It often throws the warning “not cleanly unmounted.” Windows’ hibernated kernel leaves the NTFS volume marked as in use, so Linux refuses to mount it for writing to avoid corruption.
There was also an update that remained in a fail-and-retry loop for about two weeks. Disabling Fast Startup isn’t the answer to every troublesome update, but sometimes updates need to replace files that are actively locked by Windows, and a full shutdown/restart can allow that to happen.
These were problems I encountered, but the list doesn’t stop there for other setups. Fast Startup can also contribute to BitLocker recovery prompts and issues with Hyper-V, WSL2, or other virtual machine software. I’d recommend double-checking Fast Startup if you’ve been unsuccessfully troubleshooting something else.
This is the key to everything. If Fast Startup is enabled, a restart is the better option rather than a shutdown. Restarting takes a different path, and that doesn’t include the hibernation shortcut. If restarting fixes a problem that shutting down doesn’t, that’s your hint that Fast Startup may be holding you back.
Should you disable Fast Startup?
It depends less on your boot speed than how you actually use your PC
|
If you… |
Recommendation |
|---|---|
|
Dual-boot Windows and Linux |
Disable Fast Startup |
|
Regularly use USB docks or external drives |
Consider disabling it |
|
Frequently troubleshoot driver or update issues |
Consider disabling it |
|
Use an older PC with a mechanical hard drive |
Leaving it enabled may still be worth it |
|
Have an SSD and never run into these problems |
There’s little reason to change the default |
If disabling Fast Startup offers you any value, follow these steps:
- Search for Control Panel in the Start menu and open the app.
- Change the View by: setting to Large icons.
- Navigate to Power Options -> Choose what the power buttons do.
- Click Change settings that are currently unavailable, then uncheck Turn on Fast Startup (Recommended) and save the changes.
Fast Startup isn’t broken — it’s just not for me anymore
Fast Startup is only doing what it was designed to do, and several people wouldn’t hit any of these challenges even with Fast Startup enabled. But if you do, then the setting is worth checking. The reason I disabled this setting was that it prevented things from breaking randomly. If you really need to cut boot time, there are a few other options you might try.
- OS
-
Windows
- Minimum CPU Specs
-
1Ghz/2 Cores
- Minimum RAM Specs
-
4GB RAM
- Software Version
-
24H2
Windows 11 is Microsoft’s latest operating system featuring a centered Start menu, Snap Layouts, virtual desktops, enhanced security with TPM 2.0, and deeper integration with Microsoft Teams and AI-powered Copilot.