If you’re like me, you’ve probably got more than one computer configured. The problem comes when you want to re-image one of them, but don’t have an accurate idea of which software license key’s are used by individual machines. Windows makes this difficult to recover as it doesn’t store them in a logical manner where any human could find and read them.
Additionally, it’s not until late in the installation process of Windows that you even have the option to enter a key, at which time you have to call Microsoft if the key was used by a different machine. (There’s some funny logic around this related to hardware configuration changes too).
Magical Jelly Bean KeyFinder searches and displays the keys on any post Windows-95 installation:
NOTE: This not only displays the Windows key, but also other installed software like Office and even many games.