Fast startup is a feature that was first implemented in Windows 8 as Fast Boot. It was carried over to Windows 10, and it remains an option in Windows 11. It's designed to shave seconds off of your PC ...

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.

Fast Startup is failing due to underlying system inconsistencies, such as corrupted hibernation files, misconfigured BIOS settings, or outdated drivers, which disrupt the boot optimization process.