You have installed the operating system or entered the product key, but now you want to change it. How do you do it? You can use the Windows product key Activation Wizard (GUI) or the Windows Management Instrumentation (WMI) script. The Activation Wizard method is easier, but if you have to change the product key for multiple computers, the scripting method will be better.
1 Click start in the bottom left corner, then click run.
2 Type 'Regedit' in the white text field and click OK. This will open the Registry Editor.
3 Navigate to the following registry key.
Hkey_local_machine \ Software \ Microsoft \ WindowsNT \ Current Version \ WPAEvents
4 Right-click on 'OOBETimer', in the registry key that you just navigated to and then click 'Modify'.
5 Change one or more digits to any random number.
6 Click start and then click run.
7 Paste '% systemroot% \ system32 \ oobe \ msoobe.exe / a' into the white text field.
8 Select 'Yes, I want to call a customer service representative to activate Windows', then click next.
9 Click "Change product key"
10 Enter the new product key in the small white text fields and then click update.
11 Check if you have received the same message as' You have successfully activated your copy of Windows. 'if you do, reboot your computer, and you're done!
12 Make sure you are connected to the internet in the process!