For personal use, buying and using an OEM key is generally considered "grey area" but not illegal for the end-user. Microsoft's EULA (End User License Agreement) technically states OEM keys should be sold with a fully assembled computer system, but they rarely, if ever, penalize individual home users for using them on custom builds.
: Marketplaces like VIP-SCDKey , Keysfan , or Kinguin sell digital OEM keys at deep discounts. These are often "grey market" keys—surplus licenses from other regions or high-volume buyers. While they usually work, there is a small risk of the key being deactivated later if Microsoft deems it a violation of terms. How to Use an OEM License buy windows oem license
: These are significantly cheaper than Retail versions, often priced between $10 and $30 on third-party sites, compared to $139+ for Retail. Where to Buy For personal use, buying and using an OEM
: Download the official Windows Media Creation Tool from Microsoft to create a bootable USB drive. These are often "grey market" keys—surplus licenses from
: Microsoft does not provide direct technical support for OEM copies. As the "builder," you are responsible for your own troubleshooting.