This. It's no more of a license violation than getting a key from some shady reseller, but avoids having to pay or deal with said resellers. Only ever used it

This. It's no more of a license violation than getting a key from some shady reseller, but avoids having to pay or deal with said resellers. Only ever used it for activating Windows, mind, but that works perfectly. Microsoft are clearly aware of this and don't care.