Official direct downloads for Windows 8.1 ISO files from Microsoft are heavily restricted following the end of extended support on January 10, 2023, making direct public access difficult. While volume license customers can still access images, Microsoft now primarily recommends upgrading to Windows 10 or 11 due to security risks. For official support information, visit Microsoft Learn Windows 8.1 - Microsoft Lifecycle
Navigate to: https://www.microsoft.com/en-us/software-download/windows8 (If the link redirects you, search “Microsoft Software Download Windows 8.1”) download windows 8.1 disc image -iso file- - microsoft
Windows 8.1 reached end-of-support in 2023; keep it offline for maximum security. Official direct downloads for Windows 8
If the Microsoft validation page rejects your key, double-check that you are entering a Windows 8.1 key (not Windows 8 or Windows 10). Keys are edition-specific. download windows 8.1 disc image -iso file- - microsoft