up vote 1 down vote favorite
share [g+] share [fb]

I've got a Lenovo n100 laptop that's 3 years old. It dual boots the original Windows XP that came with it and Ubuntu, and I just now noticed that the XP installation, on the Task Manager, only shows 1 CPU.

The device manager does show 2 processors (it's a core duo T2300), but it looks like one of them isn't being used. Googling showed that SP2 needed a specific hot fix to enable this, but nothing shows up on SP3, and when I downloaded the said hot fix it refuses to install, saying I have a newer solution.

(Just to make things clear, I checked and it's not that Task Manager shows all CPUs in the same graph.)

Does anyone know how to fix this?

link|improve this question
feedback

3 Answers

up vote 2 down vote accepted

Run the msconfig utility, go to the BOOT.INI tab, then click Advanced.

The NUMPROC checkbox should be unchecked to use all processors.
As a test, try to check it and see what does the drop-down list contain.
If it contains only the value 1, then something is really wrong.

image

link|improve this answer
It's unchecked, and checking it does show 2 CPUs. Any other ideas? – abyx Dec 18 '09 at 15:52
1  
@abyx: try checking the /NUMPROC box and specifically selecting the 2 CPU option. reboot. does that allow use of both cores? – quack quixote Dec 18 '09 at 17:19
@~quack - that did the trick! – abyx Dec 19 '09 at 11:22
Then the question is why it needs to be explicitly set since it should not need to. Maybe it is a driver issue? Maybe the Computer entry in Device Manager is incorrect? – Synetech Feb 21 '11 at 18:18
@Synetech inc.: I don't think you will get more info out of a 2-months old post. – harrymc Feb 21 '11 at 18:22
show 1 more comment
feedback
up vote 3 down vote

Here's another possibility.

Do you have installed the uniprocessor or multiprocessor version of XP?

Uniprocessor systems have as kernel ntoskrnl.exe, while multiprocessor systems have ntkrnlmp.exe in C:\WINDOWS\system32.

Also in Device Manager, expand Computer. You should see "ACPI Multiprocessor PC". If you're seeing "Advanced Configuration and Power Interface (ACPI) PC" then this is wrong.

What do you see?
If either of the above two checks are wrong, you'll have to reinstall XP.

link|improve this answer
feedback
up vote 0 down vote

This has worked for us (from: http://www.pcreview.co.uk/forums/change-hal-out-reinstall-t2562052.html ):

  1. Disable driver signing (My Computer > Properties > Hardware...)

  2. Run this command line exactly:

    rundll32 syssetup,SetupInfObjectInstallAction ACPIAPIC_MP_HAL 128 %windir%\inf\hal.inf
link|improve this answer
feedback

Your Answer

 
or
required, but never shown

Not the answer you're looking for? Browse other questions tagged or ask your own question.