Microsoft officially stopped selling Windows 8.1 years ago, and they do not offer an Extended Security Update (ESU) program for it. To get a legal product key now, you must look to the secondary market:
: 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. buy windows 8 download
: Be cautious of ultra-cheap "product key only" listings. Microsoft warns that these are often stolen, pirated, or volume licenses not intended for private use. How to Download the Official ISO Microsoft officially stopped selling Windows 8
: You can find physical, sealed "New Old Stock" copies (DVDs with licenses) on platforms like eBay or Amazon . buy windows 8 download