While mainstream retailers like Best Buy and Amazon have largely transitioned to newer versions, you can still find Windows 8.1 product keys through several specialized software vendors and marketplaces.

: A more traditional vendor that often carries full retail versions or digital license keys, ranging from $82.49 to over $200 for original retail boxes.

Since Microsoft officially discontinued sales of Windows 8.1 years ago, you cannot purchase a product key directly from the Microsoft Store. To obtain a legitimate license in 2026, you must rely on third-party retailers that still carry residual stock or specialize in the resale of digital keys. Reputable Third-Party Retailers

: Lists Global MS Products Digital Activation Keys for approximately $32.40 .

: Offers digital keys for Windows 8.1 Professional (OEM) at competitive prices, typically around $16.38 .

Before purchasing a new key, it is worth verifying if you already have one available to you: Find your Windows product key - Microsoft Support