You may want to change the product key, because you have a pirated version of Windows 7 and now you have recently got a full version of Windows 7 Operating system; or you have not registered your Windows 7 yet and is bothered by the Windows Genuine Advantage (WGA) window constantly popping on your desktop reminding you to active your Windows 7. There are two ways to change/update or delete Product Key in Windows 7.
Using command prompt / DOS
Using the command line it is easy to change and/or update the windows 7 Product Key just following the steps. Endure you have the new product key handy and also you are logged in as an Administrator. To open the command prompt, Click Start and select Run, on the windows type cmd. This will open your command prompt window. Start by typing the following command: slmgr.vbs -upk, and hit the Enter key on your keyboard. What this does is, it deletes any existing product key already linked with the Windows 7 or clears up the space for you enter a new product key.
Now you should be on a new line. Here type slmgr.vbs –ipk xxxxx-xxxxx-xxxxx-xxxxx-xxxxx and hit the entre key. Remember the Product key is a 25 alphanumeric code that will be on the Windows 7 DVD package. Replace the x in the command with the actual product key and ensure you put all dashes (-) and use the spaces in the command above. This command will entre the new product key and allows Microsoft to verify if it is a genuine product key.Now in the new line enter the command slmgr.vbs –ato. This will activate the product key.
Using Control Panel
If you are not comfortable with the command prompt, you can easily change the product key info from theControl Panel. In Control Panel select System and Maintenance (this option will be there only if you are in Classic view) and then select System. This will take you to System Properties window, here click on the link which says Change product key; this will be next to Product ID: towards the bottom of the System properties window. This will open the Windows Activation wizard window, here enter you Product Key (found with the Windows 7 DVD package). Once you enter the product key, click Next and it will activate the key by first connecting to the internet to ensure if this is genuine product key. Make sure you have your Internet connection on at this time.
You can also access the System Properties without going into Control Panel. Just right click on your My Computer icon and select the last option Properties. This will direct you straight to the system properties window and follow the steps as mentioned above (Using Control Panel).
Windows 7 had very strict safety regulations, so ensure you run a genuine version of Windows 7 and activate the operating system as soon as it is installed without getting your programs locked.