FAQ for Windows Product Key Viewer v1.07   

Does Windows Product Key Viewer work with Volume License Keys (VLKs) or Multiple Activation Keys (MAKs)?

Yes when you run Windows Product Key Viewer it will display the Volume License Key (VLK) of all versions Windows, except for Vista or higher. Microsoft changed the way VLKs are handled in these operating system.
Windows Vista, Windows 7, Windows 2008, Windows 10 VLKs have been replaced with Multiple Activation Keys (MAKs) that either activate copies through a local Key Management Server (KMS), which in turn reports back license usage to Microsoft, or activates directly in communication with Microsoft. Currently our Windows Product Key Viewer does not report these MAKs properly. You might see our product display the Windows Vista, Windows 7, Windows 2008 and Windows 10 License Key as BBBBB-BBBBB-BBBBB-BBBBB-BBBBB

Vista License Key

In a future version of Windows Product Key Viewer we will have support for Multiple Activation Keys (MAKs) on Windows Vista, Windows 7, Windows 2008 and Windows 10.