Computer doesn’t power down when users shut down
In some cases, Windows XP’s Setup program can misidentify the power management scheme in a computer’s BIOS as Advanced Power Management (APM) instead of Advanced Configuration Power Interface (ACPI). When this happens, users will notice that the computer no longer automatically powers down when they shut down Windows XP. Instead, they’ll see the message It Is Now Safe To Turn Off Your Computer and be forced to manually press the power button to turn off the computer.
You can verify this problem by checking the power management configuration in two places—Device Manager and the Control Panel. To quickly access Device Manager, select Start | Run, type Devmgmt.msc
in the Open text box, and click OK. When you see the Device Manager window, locate and open the System Devices item. If Setup identified the system as having an APM-compliant BIOS, it will be listed as a Standard PC in the System Devices tree. (If it were identified as having an ACPI-compliant BIOS, you would see it listed here as a Microsoft ACPI-Compliant System.)
To check the power management configuration in the Control Panel, open the Control Panel from the Start menu. If the system is using Category View, select Performance And Maintenance and then click the Power Options icon. If the system is using Classic View, just click the Power Options icon. If Setup identified the system as having an APM-compliant BIOS, you’ll see an APM tab in the Power Options Properties dialog box. (If the system were identified as having an ACPI-compliant BIOS, you wouldn’t see an APM tab.)
You may be able to fix this problem with a BIOS update. To begin, check with the computer manufacturer’s Web site to see if it’s providing the latest BIOS update. If you’re troubleshooting an off-brand computer, you may be on your own as far as tracking down the BIOS update. Here’s how
Once you obtain and install the BIOS update according to the manufacturer’s instructions, you must perform what I call a Refresh Installation, in which you reinstall Windows XP on top of an existing Windows XP installation. You must perform this reinstall operation because the power management features are tied to a special power management Hardware Abstraction Layer (HAL). During the Refresh Installation procedure, Setup will completely redetect all installed hardware, including the updated BIOS, and rebuild the power management HAL as well as the part of the registry in which information about the installed hardware is stored.