Symptoms
- PC sometimes won't fully shut down or boots oddly after 'shutting down'
- Problems appear worse after adding new hardware or dual-booting another OS
- A full restart often works better than powering off and on
- Occasional black screens or hangs specifically after using Shut Down rather than Restart
Likely causes
- CommonFast Startup conflicting with recently added hardwareSaved system state from before a hardware change can mismatch the new configuration.
- CommonFast Startup interfering with dual-boot setupsIt can lock the drive in a way that prevents another OS from mounting it properly.
- PossibleCorrupted hibernation file used by Fast StartupSince Fast Startup relies on a hibernation-like file, corruption there can cause boot issues.
- PossibleDriver that doesn't fully reset between fast startsSome drivers don't reinitialize correctly when the system doesn't fully power off.
What to do
- Try a full Restart instead of Shut Down and Power On to see if that avoids the problem, since Restart doesn't use Fast Startup.
- Open Control Panel > Power Options > Choose what the power buttons do, click 'Change settings that are currently unavailable,' and uncheck 'Turn on fast startup.'
- Fully shut down the PC after disabling the setting, then power it back on to test.
- If you dual-boot with Linux or another OS, keep Fast Startup disabled, since it's a known source of boot conflicts in that setup.
- If problems persist after disabling Fast Startup, check Device Manager for driver issues as described in other startup guides.
- Update BIOS/UEFI firmware and chipset drivers from the manufacturer's site, since these interact closely with power state handling.
- If disabling Fast Startup resolves it, leave it off; the speed difference is usually minor on an SSD.
When to call a pro
This is a settings-level fix; if boot problems continue after disabling Fast Startup, treat it as a separate startup issue and consult the relevant guide or a technician.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.