AMD64 to AMD64 X2 w/o OS Reinstall?

Hello,

I've been a computer/network pro for 20+ years, but I've been out of the
"biz" for a couple years or so now. I am currently running WinXP Pro
XP2 and a single-core socket 939 AMD64 3800+ on my main PC (1GB RAM dual
channel), and although I'm not ready to install Vista on my main machine
yet, I'd really like to upgrade to a dual-core CPU. (I understand that
even XP can benefit from that extra core, and if I do this upgrade, I
will also add another gig of RAM.)

In the past, however, I recall that adding additional processor(s)
required updating the HAL in the OS, and I'm not wanting to
reinstall/reconfig WinXP right now. (Did it a few months ago with
RyanVM's slipstream packs.)

Anyway, I vaguely remember reading something that WinXP can handle
adding a second core w/o an OS reinstall. Can anyone tell me
definitively if this is true, and if so, what actions I must take to
make the CPU upgrade go as smoothly as poss? I have to replace a
heatsink/fan on the mainboard pretty soon, so if I'm going to replace
the CPU, now's the time to do it.

BTW, I'm running an Epox 9NPA+Ultra mainboard with the latest BIOS and
latest nVidia unified drivers (6.86), along w/ latest nVidia video
drivers for my GeForce 6600. Also have *lots* of SATAII disk space. The
system is running very well but could use a little more "oomph" if you
know what I mean. Am not a gamer, but I'm as much a power user as
I can be out of the field.

Further, I've done some googling on this issue but haven't found a
consensus. Any thoughts and pointers gratefully accepted.

Thx and Regards,

Margaret, the old MCSE

Margaret wrote:
> Hello,
>
> I've been a computer/network pro for 20+ years, but I've been out of the
> "biz" for a couple years or so now. I am currently running WinXP Pro
> XP2 and a single-core socket 939 AMD64 3800+ on my main PC (1GB RAM dual
> channel), and although I'm not ready to install Vista on my main machine
> yet, I'd really like to upgrade to a dual-core CPU. (I understand that
> even XP can benefit from that extra core, and if I do this upgrade, I
> will also add another gig of RAM.)
>
> In the past, however, I recall that adding additional processor(s)
> required updating the HAL in the OS, and I'm not wanting to
> reinstall/reconfig WinXP right now. (Did it a few months ago with
> RyanVM's slipstream packs.)
>
> Anyway, I vaguely remember reading something that WinXP can handle
> adding a second core w/o an OS reinstall. Can anyone tell me
> definitively if this is true, and if so, what actions I must take to
> make the CPU upgrade go as smoothly as poss? I have to replace a
> heatsink/fan on the mainboard pretty soon, so if I'm going to replace
> the CPU, now's the time to do it.
>
> BTW, I'm running an Epox 9NPA+Ultra mainboard with the latest BIOS and
> latest nVidia unified drivers (6.86), along w/ latest nVidia video
> drivers for my GeForce 6600. Also have *lots* of SATAII disk space. The
> system is running very well but could use a little more "oomph" if you
> know what I mean. Am not a gamer, but I'm as much a power user as
> I can be out of the field.
>
> Further, I've done some googling on this issue but haven't found a
> consensus. Any thoughts and pointers gratefully accepted.
>
> Thx and Regards,
>
> Margaret, the old MCSE

"HAL options after Windows XP or Windows Server 2003 Setup"
http://support.microsoft.com/kb/309283/en-us

From a KB search on "acpi multiprocessor", which is my current
HAL on Win2K, with a hyperthreaded P4 (two virtual cores). The
article suggests if the current HAL is the correct one,
the driver needed for the second core, can be installed
automatically. Verify the HAL currently being used, via
Device Manager.

I think I've enabled and disabled hyperthreading at least once
on my system, without any consequences. (I didn't even think
about the HAL, when doing my experiments...)

Best guess,
Paul