Window$ XP no se apaga, pero dice que ya se puede apagar

Hola, torpedo,

en mi ordenata resulta que tengo XP SP1, y al darle a Inicio -> Apagar, en vez de apagarse, sale el logotipo del Window$ con un mensajito que dice: "Ahora ya puede apagar el sistema" (o algo así), y entonces tengo que dejar pulsado el botón de encendido para que se apague definitivamente. ¿Sabéis qué hay que tocar para que se apague el ordenador solo, sin que yo tenga que pulsar el botón?

Aqui esta la solucion:

This behavior may occur if one or more of the following conditions are true: •	Your computer supports the Advanced Power Management (APM) feature, but the Advanced Configuration and Power Interface (ACP)-compliant basic input/output system (BIOS) is not configured correctly to permit the operating system to turn off the power supply.
•	During an upgrade of the operating system, Windows does not detect that the computer is ACPI-compliant.
•	An OEM device driver or service is installed on your computer that is preventing the computer from correctly shutting down.
•	Your computer is not ACPI-compliant.
	Back to the top
RESOLUTION
To solve this problem, follow these steps:	Back to the top
Step 1: Enable Advanced Power Management support1.	Click Start, click Control Panel, and then double-click Power Options.
Note If you are using Windows XP, click Switch to Classic View in Control Panel to more easily follow these steps.
2.	Click the APM tab.
Note If you are using multiple monitors, the APM tab may not be available.
3.	Select Enable Advanced Power Management Support, and then click OK. 
	Back to the top
Step 2: Confirm that the computer's CMOS/BIOS settings are correct 
Warning This procedure may involve changing your computer's complementary metal-oxide semiconductor (CMOS) settings and altering the BIOS. Incorrect changes to the BIOS of your computer may cause serious problems. Change the computer's CMOS settings at your own risk.
Incorrect or damaged CMOS and BIOS settings can cause startup and shutdown problems. For information about the correct CMOS and BIOS settings for your computer and about how to check and change these settings, see the documentation that came with your computer or contact the manufacturer. To confirm that the computer's BIOS is current, contact the computer manufacturer to inquire about the latest BIOS update that is available for your computer.	Back to the top
Step 3: Verify that the computer is ACPI-compliant1.	Click Start, click Control Panel, and then double-click System.
2.	Click the Hardware tab, and then click Device Manager. 
3.	Expand the Computer branch. A specification that is similar to one of the following will appear: 	•	ACPI Multiprocessor PC
•	ACPI Uniprocessor PC
•	Advanced Configuration and Power Interface (ACPI) PC
•	Compaq SystemPro Multiprocessor or 100% Compatible
•	MPS Uniprocessor PC
•	MPS Multiprocessor PC
•	Standard PC
If your computer is listed as Advanced Configuration and Power Interface (ACPI) PC, go to "Step 4: If the computer is ACPI-compliant." 
If your computer is listed as a Standard PC, the issue will occur. However, you may be able to work around this issue. Go to "Step 5: If the computer is not ACPI-compliant."
If your computer is listed as a Standard PC, but you are sure that the computer is ACPI-compliant, go to "Step 4: If the computer is ACPI-compliant."
	Back to the top
Step 4: If the computer is ACPI-compliant
If your computer is ACPI-compliant, follow these steps: 1.	Click Start, click Control Panel, and then double-click Add or Remove Programs. 
2.	See if any one of the following programs is installed: 	•	Logitech mouse drivers
•	Adaptec/Roxio software
•	Zone Alarm
3.	If any one of these programs is installed, either contact the manufacturer of the program for an updated version or temporarily remove the program. 
4.	Try to shut down the computer to see if the issue is resolved.
5.	If the issue still occurs, use Task Manager to determine the programs that are currently running on the computer. Manually quit each program that is listed in Task Manager, and then shut down and restart the computer to test if the shutdown problem is resolved. To do this, follow these steps: 
Note All programs that are currently running on the computer may not be listed in the Applications tab of Task Manager. 	a. 	Press CTRL+ALT+DELETE, and then click Task Manager. 
b. 	Click the Applications tab.
c. 	In the Task column, click the program that you want to quit, and then click End Task. 
d. 	Quit Task Manager.
e. 	Shut down the computer.
6.	If the issue still occurs, contact the manufacturers of any additional devices on your computer, such as video adapters or sound cards, to obtain the latest drivers for the devices. For information about how to contact a vendor, click the appropriate article number in the following list to view the article in the Microsoft Knowledge Base: 
65416 (http://support.microsoft.com/kb/65416/) Hardware and Software Third-Party Vendor Contact List, A-K 
60781 (http://support.microsoft.com/kb/60781/) Hardware and Software Third-Party Vendor Contact List, L-P 
60782 (http://support.microsoft.com/kb/60782/) Hardware and Software Third-Party Vendor Contact List, Q-Z 
7.	If the issue still occurs after you install current drivers, you may be able to work around this issue by converting the computer to be ACPI-compliant by changing the driver for the item under the Computer branch.
Important This procedure contains information about changing the Hardware Abstraction Layer (HAL) driver. Before you continue, make sure that the computer is ACPI-compliant, and make sure that you know how to restore Windows if a problem occurs. 
For additional information, click the following article number to view the article in the Microsoft Knowledge Base: 
237556 (http://support.microsoft.com/kb/237556/) How to troubleshoot Windows 2000 Hardware Abstraction Layer issues 
Warning Modifying the HAL incorrectly can cause serious problems that may require you to reinstall your operating system. Do not try to change from a standard HAL to an ACPI HAL unless you are sure that the computer is ACPI-compliant. For example, determine if the ACPI HAL is supported before you upgrade your operating system, or confirm that the computer supports ACPI by inspecting the BIOS. Incorrectly modifying the HAL can cause your computer to stop starting. Microsoft cannot guarantee that problems that are caused by incorrectly changing the HAL can be solved. Change the HAL at your own risk.
If you are sure that your computer is ACPI-compliant, follow these steps: a. 	In Control Panel, double-click System.
b. 	Click the Hardware tab, and then click Device Manager.
c. 	Expand the Computer branch, and then double-click the detected HAL. For example, double-click Standard PC. 
d. 	Click the Driver tab, and then click Update Drivers. 
Note You can only change or update your HAL from Device Manager under Computer Type when you change from a Standard PC HAL to an ACPI HAL. If you change from an ACPI HAL to a Standard HAL, you may not be able to start your computer.
	Back to the top
Step 5: If the computer is not ACPI-compliant
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.

A la primera, oiga, ha sido habilitar el "Advanced Power Management support1" ese y ya apaga como mandan los cánones. Muuuuchas gracias ;.)