Fast Startup on Windows is meant to speed up the boot time. By putting the computer into a hibernation-like state by saving the system state to the disk, the next startup is faster than a cold boot. Unlike hibernation, it doesn't save your open programs and processes to the drive, but it's still beneficial. That said, Fast Startup can amount to little time savings and a lot of weird Windows behavior. For users running Windows on a modern SSD, Fast Startup can be safely disabled. Enable it only if you experience a significant slowdown in the boot time.

4 Bypassing a traditional shutdown isn't ideal

You need a rest every once in a while

You might not turn your PC off as often as you used to, relying on the sleep and hibernate modes, but a conventional shutdown has its uses. Your components need proper power cycling after a while, and Fast Startup bypasses this process. What it also does is prevent flushing background processes, resetting Windows services, and fixing other random Windows shenanigans that a shutdown or restart does.

With Fast Startup enabled, shutting down your system will skip the regular maintenance and cleanup that a cold shutdown performs for you. You might not notice any downsides immediately, but over time, your system will show the signs. Disabling Fast Startup is the better option if your SSD is fast enough for a swift boot anyway.

3 Your Windows updates might not work as intended

You probably won't know it's Fast Startup at fault

Many Windows updates require a proper shutdown and restart cycle to take effect. Without Fast Startup, things might go smoothly, but enabling it can interrupt the proper installation of updates. This can create system instability, unexplained behavior, and missing features & security updates. You might not even realize that Fast Startup is the culprit, since you might have enabled and forgotten about it long ago. Hence, keep it disabled if you update your Windows regularly. If you're like me, however, and keep Windows Update disabled, then go ahead and enable Fast Startup.

2 Dual-boot systems can come undone

Stay away from Fast Startup

Those of you who run Windows and Linux on the same drive should keep Fast Startup disabled. This is because shutting down Windows via Fast Startup mimics a hibernation-style state and doesn't release the hardware completely. The other OS, say, a Linux distro, will be unable to boot properly — you might not be able to boot at all, or find critical services like Wi-Fi or Bluetooth not working. In some cases, it can also lead to data corruption or data loss, so avoid Fast Startup on dual-boot systems completely.

1 Wake-from-sleep bugs can become more frequent

I'm speaking from experience

Another annoying aspect of Fast Startup that might affect your PC is slower wake times, network disconnects or slow reconnect times, and unusual peripheral issues like RGB controllers not working. While this might not affect everyone, Fast Startup is known to cause these issues on some systems, since the full hardware reinitialization is skipped. A cold boot, on the other hand, resets your hardware, and prevents such weird behavior.

PCs with modern SSDs shouldn't bother with Fast Startup

The gains from Fast Startup might be too slim, and considering the problems it can create on your PC, it's best to keep it disabled. Chances are, you have a modern NVMe SSD on your system, and you don't need too much help for a fast boot process. Many users even report slower boot times with Fast Startup, so you might want to experiment by toggling it on and off, and see what works best for you.