This is the most critical step. The T420 came with two graphics options:
| Hardware | What Windows Shows | Driver to Install | | :--- | :--- | :--- | | Intel AMT | “PCI Simple Communications Controller” | Intel Management Engine Interface | | Fingerprint Reader | “Unknown device” or “Biometric device” | Lenovo Fingerprint Reader Driver | | ThinkPad Hotkeys | “Unknown device” with ACPI ID | Lenovo Hotkey Features Integration | | Power Manager | “ACPI\LEN0068” | Lenovo Power Management Driver | lenovo thinkpad t420 drivers
Installing drivers randomly can cause conflicts. Follow this sequence: This is the most critical step
Required to make your volume, brightness, and other shortcut keys work. and other shortcut keys work.