In the device manager, you will find something starting with "ACPI\IFX0102" under Device Instance Id of an "Unknown Device." This driver is for the Trusted Platform Module (TPM) which is only applicable to Windows Vista. Often it will appear after a BIOS update or on a newer motherboard running an older OS (e.g. Windows XP). If a driver is not provided by your motherboard manufacturer, it is recommended to disable the device.
If I remember what I forgot, I have not forgotten it.
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