I guess I'm more interested in why the system changed behavior after the lockup than the specific symptom it exhibits. You may have corrupted a portion of the Registry or some other critical system file. Do you have any Event Log entries? Are any other features acting strangely?
There is a Registry entry that controls automatic power down, but it is a legacy entry from NT. Windows 2000 uses ACPI to handle powerdown events. That?s what has me wondering about any damage done to your system files.
Anyway, here is the Registry entry that controls automatic power down.
Key: HKLM | Software | Microsoft | Windows NT | CurrentVersion | Winlogon
Data: 1 (REG_SZ)
A standard Windows 2000 machine running an ACPI-compliant HAL should not need this setting to perform an automatic shutdown.
This was first published in February 2001