Restarting Windows and shutting it down aren't the same thing, and Fast Startup is why

Restarting and shutting down your computer are not the same processes, and Fast Startup is the reason for this difference. When you shut down your PC, it starts from scratch, but restarting provides a more thorough reset. This is mainly due to Fast Startup, a feature introduced in Windows 8. Fast Startup speeds up the boot process by saving a part of the system state instead of starting from scratch.

While this reduces boot time, it also means that shutdown doesn't completely reset your PC. This could cause issues that persist even after you shut down and restart your computer. Fast Startup is enabled by default, so you may not be aware of this behavior. When you click Shut down, Windows closes applications, signs you out, and saves the kernel session and driver state to a hibernation file called hiberfil.sys.

The next time you turn on your PC, Windows restores this saved state, carrying over the system state rather than starting fresh. This is why some hardware driver issues might persist despite a shutdown. Opening Task Manager and checking the Up time counter in Performance - CPU can confirm this, as Windows keeps tracking the kernel session across multiple shutdowns.

Restarting is the better option when fixing driver-related problems, as it bypasses Fast Startup and starts a full boot cycle, which is more likely to resolve temporary glitches. Microsoft introduced Fast Startup to address slower boot times on mechanical hard drives, but with the rise of SSDs, the impact of Fast Startup has diminished.

If you want a proper shutdown, you can disable Fast Startup via Control Panel or the command powercfg -h off. However, if you merely need a normal shutdown, you can bypass Fast Startup temporarily by holding Shift while selecting Shut down or using the command shutdown /s /t 0.