How can I change my software activation code for Windows xp pro?

Any idea how I can change my COA number before activation, I had to use a sample COA code since the one on my laptop wasn't working%26gt; So now I bought a new Windows XP pro operating system and need to change the COA code before activation..How can I change my software activation code for Windows xp pro?
Editing the registry

Begin by opening the Registry Editor and navigating to

HKEY_LOCAL_MACHINE\Software\Microsoft\?Version\WPAEvents



In the right pane, right-click the ODBETimer binary value and select Modify. Change at least one character of this value to either a number from 0 to 9 or to a letter from A to F, then click OK and close the Registry Editor. This renders the current product key invalid and deactivates Windows.



Now, it檚 time to reactivate Windows using your new product key. Click Start | Run and enter the command:

%systemroot%\system32\oobe\msoobe /a





where %systemroot% is your Windows directory. In many cases, this command will look like:

C:\windows\system32\oobe\msoobe.exe /a





At this point, Windows will launch the Product Activation Wizard.



Select the option to telephone a Microsoft customer service representative to activate Windows, as shown in Figure A, and click Next. Now, select the Change Product Key option and enter your new product key as shown in Figure B. Finally, click Update and close the window. If Windows returns you to the previous screen, just select the Remind Me Later option. When the wizard is finished, reboot the system.



When Windows reboots, your next step will depend on which Windows XP version you are using. If you have XP Home or Professional, you檒l be prompted to reactivate your copy of Windows through the normal activation process. If you have XP Corporate, no activation is required and your machine should have a valid product ID. You can verify this by running the %systemroot%\system32\oobe\msoobe.exe /a command again. When the wizard loads this time, you should see a message indicating that your copy of Windows has already been activated.



G'luck!



(check the last paragraph in the source link for more information)How can I change my software activation code for Windows xp pro?
During installation of the OS!