: Retail keys are transferable to other PCs, while OEM keys (like those from Kinguin or Eneba) tie themselves to the first motherboard they activate on and cannot be moved.
: Avoid "product key only" listings that seem too good to be true. Many separate keys sold cheaply online are actually stolen, pirated, or volume licenses not intended for individual use. Official packages including a Certificate of Authenticity (COA) or retail boxes are more reliable for long-term use.
Microsoft officially , and no longer sells product keys directly. To acquire a key in 2026, you must rely on third-party retailers, "gray market" key sellers, or secondary markets like eBay. Recommended Retailers & Pricing