I just changed my operating system from Windows 7 Home Premium to Windows 7 Ultimate. Activating Windows with the product key didn’t work, even after retyping it several times. What options do I have?
Make sure to adhere to my instructions carefully. Please confirm the key you're using, whether it's the HP key or the Ult key.
Confirm your input is correct—did you mean to specify the numbers and symbols properly? Are you asking about validation messages, calling Microsoft support, or identifying the type of key? What installation state are you in: new or updated? Which version of Windows were you using and which disk/ISO?