Her blood ran cold. She downloaded a low-level ACPI probe tool. The command acpidump -t returned thousands of lines of code. Near the bottom, buried in the DSDT (Differentiated System Description Table), she found it.
Once you have the Acpi Fnbt0000 driver working again, prevent regressions with these best practices: Acpi Fnbt0000 Driver
When this driver is missing, it typically appears as an in the Windows Device Manager under the "Other devices" category. Her blood ran cold