Retail vs OEM Windows licences: what transfers and what doesn't

Windows licences are commonly sold through a small number of distinct channels, and the difference between them comes down to one thing: who is responsible for the PC the licence is tied to, and under what agreement it was activated.

The three channels, briefly

Retail licences are issued to you, the end user, for your own use on your own hardware, with the transfer rights described below. OEM (System Builder) licences are issued to whoever assembled the PC it was first installed on — under Microsoft's own System Builder terms, that party takes on the support obligation for the machine, and the licence is tied to that specific piece of hardware for its working life. Volume-licensed editions (sold to organisations under agreements like Volume Licensing or through Microsoft 365 subscriptions with included Windows entitlements) follow entirely separate terms again, are not something an individual typically buys directly, and are outside the scope of what a retail reseller sells.

BTD Soft sells retail licences. If you're evaluating a licence from any other source, checking which of these three channels it actually came from — not assuming — is the first thing worth doing, because the answer changes what you can and can't do with it later.

The one fact that matters

A Retail licence can be deactivated on one PC and activated on another over time, because it's licensed to you rather than to a specific machine. An OEM/System Builder licence is not designed to move to different hardware, even hardware you build yourself, because the licence's support relationship is with the system it was originally installed on.

How to check which type you have

On the PC in question, open an elevated Command Prompt and run:

slmgr /dli

This reports the licence description, including whether it was activated through a retail or OEM channel. For a more detailed readout including the specific channel, slmgr /dlv shows additional licensing detail. If you bought a pre-built PC from a manufacturer, it very commonly shipped with an OEM licence — manufacturers routinely license this way to keep the cost of pre-built systems down. If you bought a standalone product key separately from any hardware, check the actual licence description reported by slmgr /dli rather than assuming from how it was purchased — the seller's own listing should also state the licence type plainly, and if it doesn't, that's worth asking about directly before relying on an assumption either way.

What this means in practice

• Retail: buy once, and you can move the same licence to a new PC later, following the transfer steps in our companion guide — though moving a licence doesn't happen automatically just because you deactivated the old key; see that guide for what activation on the new PC actually requires.
• OEM/System Builder: intended to stay with the original hardware for its working life. If that hardware is retired, the licence is not designed to move with you to a different machine.
• Volume-licensed: governed by the organisation's own agreement with Microsoft, not something to buy or resell individually.

Choosing which to buy

If you expect to upgrade or replace this PC's hardware within the licence's lifetime and want to keep using the same key, a Retail licence is the one built for that. If you're licensing a machine you don't expect to move the OS off of, either Retail or OEM works equally well for that single PC's lifetime — the difference only matters when hardware changes.