Update the system BIOS to the latest version provided by the manufacturer (Dell, HP, Lenovo, etc.). Ensure the TPM is explicitly Enabled in BIOS settings. Once enabled, the Windows Plug and Play service will automatically bind the tpm.sys driver to the hardware ID, resolving the "Unknown Device" flag.
The presence of this device as an "Unknown Device" is rarely a driver corruption issue. It is almost exclusively caused by one of three scenarios:
In a perfect world, Windows would automatically detect your TPM, load the driver, and hide this device from view. But when you see a yellow triangle next to ACPI MSFT0101 , it usually means one of three things:
Or simply a failed probe of the TPM device.
Enables full disk encryption without a physical TPM chip.
To suppress the error and prevent boot delays: