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IT Support & Hardware · Intermediate

Fast Startup

A Windows feature that hibernates the kernel session at shutdown to speed the next boot.

Definition

Fast Startup saves kernel state to hiberfil.sys on shutdown, so a 'shutdown' is not a full cold boot; Restart performs a full boot. It can interfere with dual-boot setups, Wake-on-LAN, and driver updates. Disable it in Power Options if issues arise.

Example

A problem persists after shutdown but clears after Restart because Fast Startup is enabled.

Exam tip

Restart, not Shut down, gives a fresh kernel when Fast Startup is on.

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