HyperThreading isn't detected by XP

I've re-built my P4 since my FX-55's motherboard keeps pestering me, but I've ran into a very strange problem. HT isn't detected in XP, even trying to force it to "ACPI Multiprocessor" as the computer type - it doesn't exist!

The only computer type I see is "Standard PC" - even unticking "Show compatible hardware" only shows "Standard PC". Any ideas why I can't get ACPI Multiprocessor to show so I can use the HT?

HyperThreading and ACPI are enabled in the BIOS. I've got an MSI 875P Neo-FIS2R motherboard with a Pentium 4 3.2GHZ Extreme Edition (Gallatin core) running Windows XP Pro SP2.

Cheers!

[Paul K]

Is this a new/ clean install of windows since the rebuild?

Yeah. Formatted the drive and installed from scratch.

How many processors are listed in device manager?

Edit - When you installed from scratch, did you change the HAL?

I can't even find the CPU in the device manager

I don't understand what you mean by HAL either

[Graham M]

Is it enabled in the BIOS?

update the processor driver????

[Paul K]

HAL = Hardware Abstraction Layer. It's how windows recognises your hardware, when you do a major hardware change (especially one that changes your power management hardwre) it can cause problems with the HAL that a new install is needed to fix.
http://support.microsoft.com/?id=309283

Originally Posted by Paul

HAL = Hardware Abstraction Layer. It's how windows recognises your hardware, when you do a major hardware change (especially one that changes your power management hardwre) it can cause problems with the HAL that a new install is needed to fix.
http://support.microsoft.com/?id=309283

According to the link though a clean install wouldnt effect that only a change of hardware install with an existing os

Scott was it running correctly before the install? I see a chance its faulty afterall you was given it so maybe?

Do you have ACPI enabled in bios? I remember when I used a P4 many moons ago now you cant switch hyperthreading on in bios without reinstalling windows so is there a chance it was disabled before and you did the reinstall and enabled it?

Originally Posted by Zeph

Is it enabled in the BIOS?

Yup.

Originally Posted by zinglebarb

update the processor driver????

Can't even see the CPU in the device manager. Doing a full scan for hardware doesn't detect it either.

EDIT: It was working fine before the re-install. And yes it was turned off before the install, but that's why I should be able to change the "Computer" in device manager to ACPI Multiprocessor (I did the same thing with the other system sitting next to me, which is also running XP Pro and a P4 3.2).

windows update should find driver for it if you need one

Windows update doesn't show anything for the CPU.

Originally Posted by Electrolyte

Yup.

Can't even see the CPU in the device manager. Doing a full scan for hardware doesn't detect it either.

EDIT: It was working fine before the re-install. And yes it was turned off before the install, but that's why I should be able to change the "Computer" in device manager to ACPI Multiprocessor (I did the same thing with the other system sitting next to me, which is also running XP Pro and a P4 3.2).

I dont think thats the case you will need to install a fresh windows

Originally Posted by zinglebarb

I dont think thats the case you will need to install a fresh windows

I was afraid of that

Originally Posted by Electrolyte

I was afraid of that

Yup, sounds like you are going to do a clean install and choose the ACPI Multi Processor HAL in the options...