When you search for Windows or Office keys you will see the terms OEM, retail and volume. Here is what they mean.
Retail licence
Sold to individual consumers. It can usually be moved to a new PC if you uninstall it from the old one. It carries Microsoft's full retail price.
OEM licence
Pre-installed by PC makers (Dell, HP, Lenovo…) or sold to system builders. It is tied to the first computer it is activated on and cannot be transferred to a different PC.
Volume licence (MAK / KMS)
Issued to organisations through Microsoft's volume licensing programmes and activated with a Multiple Activation Key (MAK) or a Key Management Service (KMS) server.
Which is right for you?
- Building a new PC or reinstalling: the edition (Home/Pro) matters more than the channel — make sure the key matches the Windows you install.
- Always check the product page for the exact licence details: number of devices, validity (lifetime or yearly) and supported platform.
- Choose a seller that offers a replacement or refund if activation fails.
Every KeyForPC product lists its licence terms, and our Refund Policy covers keys that don't activate. Browse all products →