: Sites like Mr Key Shop and Digital License Shop still list Windows 8.1 Pro retail and OEM keys. These typically offer instant digital delivery via email.
Even if you buy a key from a third party, you should always download the operating system from a verified source to avoid malware. Betting the Company on Windows 8 - Coding Horror
While Microsoft no longer sells it directly, it is still possible to acquire and run this OS if you have a specific need, such as legacy software compatibility or retro hardware. Where to Buy a Windows 8/8.1 License
