The product key that you enter when installing Windows 7 determines what version of the operating system is installed. This means a single Windows 7 DVD can be used to install the multiple editions. One question that immediately arises then is “how can I upgrade my existing version of Vista to a version that has additional features?”

The answer is to change the product key through the System applet.

  1. Right click My Computer and select Properties.
  2. Click on Change Product Key Link.
  3. Enter a new product key.
  4. Click Next to activate the new product key.