Will adding a CPU to my motherboard require me to re-install OS?

I have two computers and both have a motherboard that supports two CPUs. One has XP and the other Windows 2000.

I have been told that if I install a second CPU that I will have to re-install the operating system as well.

Can anyone give me a little insight into what is correct before I proceed.

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No it will not.
The CPU addition would be handeld through your system BIOS and not the OS.
Only very isolated instances does adding an extra processor deal with the OS. In fact, the only one I personally know of is Terminal Server for NT 4.0.
You should not have any issues.............be safe, backup  your system just in case. No matter how remote a chance of something going wrong is, it is a chance.

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oh,,,,,,and even on TS for NT 4, it doesn't require  reinstall of OS, just some config changes to make it utilize the added processor...
No, as TannerMan told you, you will not have to reinstall your system, though you might take a look at this: http://support.microsoft.com/default.aspx?scid=KB;en-us;234558
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elbereth21 is correct, you will need to update the processor driver configuration by updating the computer driver using Device Manager.
no reinstallation required as stated above
williamconradAuthor Commented:
Thanks everyone. Can I ask a followup question?

If we replace the existing CPU (1.7GH with 2.8 or 3.0GHz), does that change the answer?
I have been told that the OS reads the serial number of the CPU and will not work if the original CPU is changed.

And do both CPUs need to be the same speed?

This project seems to generate more questions as I go along.

Thanks again.
This all depends on your motherboard specs.
Almost always, but I am no expert on motherboards, the Proc's should match. As far as I know there are no cpu serial numbers hardcoded into the OS that would require a rebuild. At least, I have replaced them before without any problem.
williamconradAuthor Commented:
Thanks Tannerman.
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Windows 2000

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