Windows Update replaced Lenovo ACPI driver with generic Microsoft ACPI driver.
| Model Series | Hardware ID | Driver file | |--------------|-------------|--------------| | ThinkPad T490/X1C7 | ACPI\LEN0268 | acpivhd.sys | | Legion Y540 | ACPI\VPC2004 | acpilik.sys | | Yoga C940 | ACPI\LEN0271 | acpivpc.sys |
Get-WinEvent -LogName "System" | Where-Object $_.ProviderName -eq "LenovoAcpi" Critical events to watch: Event ID 5 (EC communication timeout), Event ID 12 (Battery method not found).
Improptu D3cold transition on PCI root port.
pnputil /enum-drivers | findstr "acpivhd" pnputil /delete-driver oemXX.inf /uninstall # Then reinstall from Lenovo package Applies to: Early 2020 drivers on Windows 10 2004+.