Driver: Acpi Fnbt0000

Run as Administrator:

sfc /scannow
dism /online /cleanup-image /restorehealth

Corrupt ACPI.sys or WDF (Windows Driver Framework) files can mimic a driver issue.

On modern Lenovo laptops (Legion, Yoga, ThinkBook), pressing Fn+Q cycles through performance profiles (Quiet, Balanced, Performance). This hardware toggle requires the ACPI FNBT0000 driver to signal the EC to change fan curves and power limits. Acpi Fnbt0000 Driver

If you have followed all steps and Fn keys still fail, the issue might not be the driver itself.

FNBT0000 is a ACPI Hardware ID assigned to a Fingerprint Sensor — typically made by Elan or sometimes Goodix / Synaptics. Corrupt ACPI

This device is embedded on laptops (Dell, HP, Lenovo, Acer) and attached via I2C or USB internally, but exposed through ACPI for power management.

If the device appears as "Unknown device" with no driver available, you can manually point to the Lenovo INF file: On modern Lenovo laptops (Legion, Yoga, ThinkBook), pressing

The primary function of the ACPI Fnbt0000 driver would be to enable the operating system to properly communicate with and manage specific hardware features, likely related to function keys or special keys on laptops. This could include:

Fnbt0000 is a vendor-specific hardware ID. The “Fn” usually hints at the Function (Fn) key on a laptop keyboard. The “bt” might refer to a button array or a proprietary bus (e.g., button bus). The number 0000 is typically a placekeeper or specific device instance.

In plain English: Acpi Fnbt0000 is the driver responsible for handling Fn key combinations, media buttons, brightness shortcuts, and other special keys on a laptop. Without it, your volume up/down, airplane mode toggle, or screen brightness keys may stop working.