Using the Windows Registry Editor incorrectly can cause serious problems that require the reinstallation of your operating system and possible loss of data. TechRepublic does not support problems that arise from editing your registry. Use the Registry Editor and the following directions at your own risk.

Editing the registry
Begin by opening the Registry Editor and navigating to
HKEY_LOCAL_MACHINE\Software\Microsoft\WindowsNT\Current 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’s 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.

Figure A

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.

Figure B