Windows 8.1 is essentially a free large update package for Windows 8, not real upgrade. So all Product Keys and Activation Keys are also working to the corresponding editions of Windows 8.1.

Below, AppNee searched through the whole Internet and screened out 7 Product Keys which are universal for all editions of Windows 8/8.1 (including all languages, both 32-bit and 64-bit); such as Retail (Full Packaged Product – FPP), OEM (Original Equipment Manufacturer), Upgrade, RTM (Release To Manufacturing), VOL (Volume Licensing for Organizations), MSDN, TechNet, Preview…

// All Product Keys //

*** These are Product Keys for Windows 8/8.1 and Server 2012 (With Update) installation (which will be asked in the process of clean or upgrade installing), not Activation Keys. But if you are looking some tool to activate your Windows system, that’s easy, you have two easiest choices:

• KMSAuto Easy (Activator for Windows 7,8,8.1 and Office 10,13)
• KMSPico (One-click to activate Microsoft Office & Windows all editions)
• Microsoft Toolkit (Windows, Office all products activator & uninstaller)
• Xiaoma KMS Activator – Perfect All Editions & Microsoft Windows & Office one-click activator
• KMSAuto Net – KMS Server based Windows & Office universal one-click activator
• KMSAuto Lite – Microsoft Windows and Office Universal offline activator
• Re-Loader Activator – Offline activator for Windows XP~10, Server 2008~2016, Office 2010~2016

// Related Links //

• Compare Windows 8.1 All Editions
• Windows 8.1 Editions Comparison Chart (JPG)
• Comparison of Windows 8 editions from Wikipedia
• Windows 10 All Editions Universal Product Keys collection