Without having to reinstall xp:
If the computer is not ACPI-compliant, you may be able to work around this issue by installing the NT APM/Legacy Device. Before you install the NT APM/Legacy device, you must first disable the Microsoft ACPI Device if it is installed.
To disable the Microsoft ACPI Device: 1. Open Control Panel, and then double-click System.
2. Click the Hardware tab, and then click Device Manager.
3. On the View menu, click Show Hidden Devices.
4. Expand Non-Plug and Play Drivers.
5. Do either of the following: • If Microsoft ACPI Driver is not listed:
In the NT APM/Legacy Support branch of the device tree, you will see the item NT Apm/Legacy Interface Node. It will show a red X to indicate that it is disabled.
Right-click NT Apm/Legacy Interface Node, and then click Enable.
After you follow these steps, Windows will shut down correctly.
• If Microsoft ACPI Driver is listed, follow these steps: a. Double-click Microsoft ACPI Driver.
b. Click the Driver tab, and then in the Type box, click Disabled.
c. Click OK, and then restart the computer.
d. When Windows restarts, repeat these steps to open the Microsoft ACPI Driver Properties dialog box, and then click the Driver tab.
Verify the following: • Disabled appears in the Type box.
• Stopped appears in the Status section.
After you verify that the Microsoft ACPI Device is disabled, continue with the following steps to install the NT APM/Legacy device:
e. Open Control Panel, and then double-click Add Hardware.
f. When the Hardware Wizard stops searching for new hardware, click Yes, I have already connected the hardware, and then click Next.
g. Scroll to the bottom of the Installed Hardware list, click Add a new hardware device, and then click Next.
h. Click Install the hardware that I manually select from a list (Advanced), and then click Next.
i. Under Common Hardware Types, click NT Apm/Legacy Support, and then click Next.
j. Click NT Apm/Legacy Interface Node, and then click Next.
k. Click Next again, and then click Finish.
The computer will now correctly shut down.