i found this article and thought it would be an interesting read. but i believe this would cause a lack of security as M$ cannot keep track of which product is where and how many there are ??

[quote]SP1 will disable Windows Update and certain features of XP running the Product ID codes:

XXXXX-640-0000356-23XXX
XXXXX-640-2001765-23XXX

To check what Product ID you are running, go:
START --> RUN --> type: regedit --> ENTER --> browse to /Software/ Microsoft/Windows/CurrentVersion --> key name "ProductID"

To replace your Product ID/code/serial number, follow these steps:
1. Run a system restore to create a new checkpoint (just in case).
2. Run regedit and go to: HKey_Local_MachineSoftwareMicrosoftWindowsNTCurrent VersionWPAEvents
3. Double click key "oobetimer" and modify at least one digit of this value to deactivate Windows.
4. START --> RUN --> type: %systemroot%system32oobemsoobe.exe /a --> Activation Screen should pop up.
5. Select second option, "Activate By Phone"
6. In the new screen, choose the option to change Product Key and type in the new product key (only corporate keys will work).
7. If it brings you back to the prior screen after entering the new key, check "Remind Me Later" and then reboot.
8. Close the "Activation Screen" and reboot your system. Enter the command from steps 2-3 again to verify your installation activation. You should see "Windows is already activated."
9. Install SP1. You are safe. [\quote]