FAQ for Windows Product Key Viewer v1.07   

The product key returned does not match the one on my sticker, why?

If you purchased your PC with Windows already installed from a large manufacturer such as Dell or Acer, it is likely that Windows was installed using an OEM key instead of the actual key for your PC. This saves you both money because it's much more efficient for these large PC manufacturers to install Windows once and then use cloning software to clone the drives. This clones the same Product Key as well.