Retail, OEM and volume are three ways Microsoft distributes the same Windows and Office software. The installed product can look identical, but the licence channel decides who may use it, whether it can move to another PC and how it activates. This guide explains each channel, how it binds to a device, and how to check which one you have.
| Retail | OEM | Volume (MAK / KMS) | |
|---|---|---|---|
| Intended for | Individuals and small businesses buying a stand-alone licence | PC builders and manufacturers, one licence per new PC | Organisations with a volume licensing agreement |
| Transfer to another PC | Allowed for stand-alone software, after removing it from the old PC | Stays with the original device | Governed by the organisation's agreement |
| Tied to hardware | Linked to the device at activation, can be moved | Linked to the first device | MAK: per activation count; KMS: renews with a local host |
| Activation method | Online or phone with a unique key | Pre-activated by the maker, or key entered by the builder | MAK: online or phone; KMS: local KMS host on the network |
| Who provides support | Microsoft | The device maker or system builder | The organisation's IT team, under its agreement |
What is the difference between OEM, retail and volume licence keys?
A retail key is a stand-alone licence you can move to another PC you own, an OEM key comes with or for one new computer and stays with it, and a volume licence is issued to organisations and activates many machines through a Multiple Activation Key (MAK) or a Key Management Service (KMS) host.
Microsoft's volume activation planning guide describes the three channels in these terms. The software itself does not change between channels. The licence terms and the activation mechanism do.
This matters because the channel decides what happens when something changes later, such as a motherboard replacement, a new PC or a company audit.
What is a retail licence key?
A retail licence key is a unique 25-character product key sold for one stand-alone installation, boxed or digital, that activates against Microsoft's activation servers and, under Microsoft's licence terms, may be moved to another device that belongs to you once it is removed from the previous device.
For Windows, a retail key creates a digital licence the first time it activates. That digital licence is linked to the device's hardware ID and can also be linked to your Microsoft account.
For Office, retail products such as Office 2024 Home and Business are usually redeemed to a Microsoft account. Retail Office installs use product IDs that end in "Retail", for example ProPlus2024Retail in the Office Deployment Tool.
What is an OEM licence key?
An OEM licence is the Windows licence a manufacturer or system builder installs on a new computer, which Microsoft describes as being activated by associating Windows with the computer's firmware before shipping, so the licence belongs to that device and can only change hands together with it.
OEM keys are also sold for custom-built PCs. They activate the same Windows features as retail keys, for example Windows 11 Pro OEM keys unlock the full Pro edition.
Cause and effect: because an OEM licence is tied to the first motherboard it activates on, replacing that motherboard is usually treated as a new PC. Activation may then fail with error 0x803FA067 or similar, and reactivation may be refused under OEM terms. We cover the fixes in our 0x803FA067 hardware change guide.
What is a volume licence, and what are MAK and KMS?
A volume licence is issued to organisations under agreements such as Enterprise Agreements and activates either through a Multiple Activation Key (MAK), which activates computers directly with Microsoft up to a set count, or through a Key Management Service (KMS) host running inside the organisation's own network.
How MAK activation works
Microsoft describes a MAK as acting like a retail key, except that it can activate multiple computers. Each MAK has a preset number of activations based on the licences the organisation bought. Once activated, a MAK installation stays activated, because Microsoft's slmgr documentation describes MAK and retail activation as perpetual.
How KMS activation works
KMS is designed for larger networks. Microsoft's KMS activation planning page states that KMS activations are valid for 180 days and that clients try to renew every seven days by contacting the KMS host. A KMS host also needs a minimum number of computers, 25 for Windows client, before it activates anyone.
Advanced nuance: Microsoft publishes the generic KMS client keys (GVLKs) openly, and states they cannot be used with retail editions and will not activate without a KMS host on your network. This is why a "KMS key" sold to a home user is a red flag. It either needs an unauthorised KMS emulator, or it stops working when the 180-day window runs out.
Which licence type should I buy for a home PC or a business?
For a home PC, a retail key suits buyers who expect to replace the computer and an OEM key suits a build that will stay as it is, while small businesses usually buy retail or OEM keys per device and larger organisations with a Microsoft agreement use MAK or KMS volume licensing.
- Single home or gaming PC you will keep: OEM is sufficient.
- PC you plan to replace in a few years: retail, so the licence can move with you.
- Office for one PC that will move later: a retail Office licence linked to your Microsoft account.
- Office LTSC for an organisation: volume editions such as Office LTSC Professional Plus 2024, deployed with the Office Deployment Tool.
What we commonly see is buyers purchasing an OEM key for a PC they upgrade every year, then needing help after each motherboard swap. If you change hardware often, a retail Windows 11 Pro licence avoids that problem. You can browse every Windows licence type in our operating systems collection.
What happens to each licence type after a motherboard change?
After a motherboard change Windows usually treats the PC as a new device and deactivates, after which a retail licence linked to your Microsoft account can normally be reactivated with the troubleshooter, an OEM licence may be refused because it belongs to the original device, and volume licences follow the organisation's agreement.
Microsoft's hardware change guidance also requires the edition to stay the same: a Pro licence reactivates Pro, not Home. If the troubleshooter route fails for a retail key, entering the same key again in Settings or using phone activation are the usual next steps.
Our guide to transferring a Windows licence to a new PC walks through each step, including the case where too many activations trigger error 0xC004C008.
How do I check if my Windows or Office licence is retail, OEM or volume?
Run slmgr /dli in Command Prompt to see your Windows licence channel, where the Description line contains RETAIL, OEM or VOLUME, and for Office 2016 or later run cscript ospp.vbs /dstatus from the Office folder, where the licence lines show the channel and activation type.
Windows: slmgr
- Press Start, type
cmdand open Command Prompt. - Type
slmgr /dliand press Enter. A small window shows the licence description and status. - For more detail, including the activation ID, run
slmgr /dlv. - To see whether activation expires, run
slmgr /xpr. Microsoft notes this is mainly useful for KMS clients, since MAK and retail activation is perpetual.
Office: ospp.vbs
- Open Command Prompt as administrator.
- Go to the Office folder, normally
cd "C:\Program Files\Microsoft Office\root\Office16". For 32-bit Office on 64-bit Windows, useProgram Files (x86)instead. - Run
cscript ospp.vbs /dstatusand read the licence lines.
Microsoft's Office volume activation tools page notes that ospp.vbs does not work for Microsoft 365 Apps, which use a different licensing model. The command shows only the last five characters of an installed key, never the full key.
Frequently asked questions
Is an OEM key genuine?
Yes, an OEM key is a genuine Microsoft licence that activates the full edition of Windows it belongs to. The difference from retail is in the licence terms, not the software: OEM is intended to stay with one device, and support comes from the device maker or system builder rather than directly from Microsoft.
What does "ProPlus2024Retail" mean?
ProPlus2024Retail is the Office Deployment Tool product ID for the retail channel of Office Professional Plus 2024. Microsoft also lists ProPlus2024Volume for the volume channel. The ID must match your key type, because Microsoft warns that using the wrong product ID means you cannot activate Office.
Can I turn an OEM licence into a retail licence?
No, you cannot convert an OEM licence into a retail licence. The channel is fixed by how the key was issued. If you need the ability to move Windows to future PCs, buy a retail licence for that purpose and keep the OEM licence with the computer it was activated on.
Why does my Windows say VOLUME_KMSCLIENT when I bought a home PC?
A home PC showing VOLUME_KMSCLIENT usually means Windows was activated against a KMS host rather than with a retail or OEM key. Outside a company network, this often points to an unauthorised KMS activator. Replace it with a genuine key, and scan the PC, because Microsoft Defender flags such tools as hack tools.
Do MAK keys expire?
A MAK activation does not expire once it has succeeded, because Microsoft describes MAK activation as perpetual. What runs out is the number of activations the key can perform. When the count is used up, new installations cannot activate with that key until the organisation requests more activations from Microsoft.