How to Reset a Windows Product Keyby Jim Campbell
Your Windows product key is the verification string Microsoft uses to validate your Windows operating system copy. The key is checked each time you update the operating system on your computer. If you buy a new Windows copy or your key is not valid, you can reset the product key in the system information screen. Before you reset the key, you must purchase a valid Windows product key for your operating system.
Click the Windows "Start" Orb in the task bar. Right-click the "Computer" icon and select "Properties." This opens the system properties window.
Click the left link labeled "Change product key." This opens a wizard that displays the current product key in text boxes.
Replace the current key with your newly purchased Windows product key and click "Next." Windows checks the validity of the current key.
Click "Finish" on the final screen. Your new product key is saved in the Windows registry settings.