All You Need to Know about Windows Licenses: Retail, OEM, SLP, VL

All about Windows licenses: Retail, OEM, SLP, VL ...
All about Windows licenses: Retail, OEM, SLP, VL …

Who has never wondered about Windows licenses  ? For many, the content of these  licenses is so opaque that it is difficult to know what one has the right and not the right to do with it. This is the ambitious goal of this article, enlighten you, and answer all the questions you can ask yourself about Windows licenses .

What are the different types of Windows licenses  ? What Windows license is installed on my PC? What is the difference between an OEM and Retail license? What happens to my Windows license if I change the motherboard or the hard disk of my PC? Ouch, that’s already a lot and believe me it’s only a beginning in front of all the shadows that must be cleared!

In this article, I will try to be as exhaustive as possible by explaining to you point by point the different types of Windows licenses and what rights you have according to the license you have (OEM or Retail). I have also put together a small FAQ at the end of this article to answer the most frequently asked questions about Windows licenses .

Are you ready to know everything and understand everything about Windows licenses ? Let’s go !

Retail License

The Retail license  of Windows is the most expensive license but also the least restrictive.

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Retail or FPP license of Windows 10 sold at 129,99 € on Amazon (on 02/03/2016)

With the product key provided , you can install Windows on any PC. If you buy a new PC (which you install yourself for example), you can install Windows on this new PC and activate it using your product key, taking care  to remove he product ke  on your old PC . In the same way, you can change all the components of your current computer (motherboard, hard disk …) without any worries, even if a reactivation of Windows will sometimes be necessary (especially if you change an essential component like the motherboard).

The Retail license is not related to hardware such as the OEM license but to the user. You must, however, respect the license to use namely a license per post . You can not use your product key to install and activate Windows on multiple PCs at the same time: your license must be installed on one PC at a time . If you try to install and activate Windows with your product key on a second PC, Windows will no longer be activated on the first PC.

The Retail license can be acquired in two different ways. First way: by purchasing the Full Packaged Product (FPP) version of Windows from an authorized reseller. The box contains the Windows installation media (a USB key or installation DVD), the product guide (or user manual), the product key and the user license. Second way: by buying and downloading the digital version (download) of Windows  from an authorized reseller (the Microsoft Store, Amazon, …). You will receive a confirmation e-mail containing the details of your order and your product key.

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Content of Retail or FPP version of Windows 10 Pro – Source:

The activation of your Retail license is done directly in Windows, by Internet or with a confirmation ID which you obtain by telephone. A new activation will be necessary if you change motherboard and / or hard drive on your machine.

In the event of a technical problem with Windows, Windows support  is performed by Microsoft.

License “Update”

The “Update” license is identical to the Retail license, except that it can only be used by updating a previous version of Windows called “qualifying” . If you buy an “Update” license, you will have to launch the Windows installer from a previous version of Windows already installed … and activated  of course?

For example, to install and activate Windows 8 in “update” version, you must launch the installation directly from Windows XP, Windows Vista or Windows 7. No matter whether this qualifying version is an OEM version, a box version or it – even an “updated” version. If you launch the installation of this “update” version on a blank partition (by starting directly on the DVD or the USB key of installation at the start of the PC for example), the activation of Windows will not work.

License “Update” of Windows 8 sold at 130,00 € on Amazon (on 02/03/2016)
Retail or FPP license of Windows 8 Pro sold for € 279.99 on Amazon (on 02/03/2016)

The terms of use are the same as the Retail license: you can transfer your license to any other PC, as long as this license is installed on one PC at a time. Price level, it is between the Retail license and the OEM license. It was launched to allow owners of a license for an older version of Windows to upgrade to a lower cost version. The “Update” license is in all respects identical to the Retail license , only the operating mode of the installation differs.

Importantly, you can not re-use the old license (that of the qualifying version of Windows) on another PC. Example: You install Windows 7 Retail version on your PC, then you update it by installing Windows 8.1 version “Update”: you will not be able to use your Windows 7 product key on another PC.

OEM license

The Original Equipment Manufacturer ( OEM ) license for Windows is the cheapest but also the most restrictive license. In general, the OEM license is intended for assemblers (companies that manufacture customized PCs such as HP, Asus, Lenovo … or the computer store at home) and system integrators: it allows to provide a pre-installed Windows at a lower cost when selling a complete configuration. When you buy a pre-installed PC with Windows , in 99% of cases you have a Windows OEM license .

However, as an individual , you also have the option of obtaining an OEM license .

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OEM license of Windows 10 Family sold at 119,99 € on Amazon (on 02/03/2016)

The big black point of the OEM license (which explains its reduced price) is that it is related to life on your machine, so it is impossible to move the license on another PC . If you have purchased a Windows OEM license in the trade, it is after you have activated Windows over the Internet or by phone with the supplied product key that the link is definitely made between your PC and your OEM license.

You can change all components of your PC without having to buy a new license, unless you change hard disk (only for OEM licenses: SLP) or if you change motherboard: in these cases, Windows will no longer be activated . But then what happens if your motherboard or hard drive goes down? If you bought a PC where Windows was pre-installed, you should contact the technical support of the manufacturer of your PC (HP, Lenovo, Dell …) to proceed with a component replacement (hard drive – only for OEM licenses: SLP – or motherboard) to preserve your Windows OEM license .

There are four types of OEM licenses, each with a different activation method:

  1. The OEM license: DM  : This is the license you have if you bought a branded PC  pre-installed with Windows 8, 8.1 or 10 . You have a genuine Microsoft Label ( Genuine Microsoft Label or GML) affixed to your device. You do not have a product key . Instead, a System Locked Pre-installation(SLP ) key is stored in the UEFI firmware ACPI MSDM (Microsoft Digital Marker) table on your motherboard, which is automatically read by the Windows Installer. You do not need to enter a product key when reinstalling Windows.
  2. The OEM license: SLP  : this is the license you have if you bought a branded PC  pre-installed with Windows XP, Vista or 7 . You have a Microsoft Certificate of Authenticity (COA) label affixed to your device. A product key is printed on the COA label but it is not this product key that is used in the first place to activate Windows! Here is how your Windows license is activated: a System Locked Pre-installation (SLP ) key and an OEM certificate are registered in the ACPI SLIC tablethe BIOS of your motherboard. This SLP key and OEM certificate are compared to the product key and OEM certificate file installed in Windows; if it’s both “match”, the activation of Windows is validated. The product key on the COA label is only provided if a reinstallation of Windows is required and for one reason or another, the offline activation of Windows via the SLP does not work. In this case, users will have to manually activate Windows by phone using the product key on the COA label. You then activate your  OEM license: COA  Windows.
  3. The OEM license: COA  : this is the license you have if you bought a branded PC  pre-installed with Windows XP, Vista or 7 , and  when you used the product key printed on the COA label (see the previous point for more information).
    Certificate of Authenticity (COA) label of Windows 10
  4. The OEM license: NONSLP (Non System Locked Pre-Installation): A product key is provided to you, as for the Retail license. Windows activation must be done by the user either over the Internet or by phone.

From a functionality point of view, the OEM version is strictly identical to the Retail version . The product key OEM: DM and OEM: SLP  are the only key that can activate Windows offline, without the need to contact Microsoft servers. They are only used by major brand PC makers like Asus, Dell, HP …

In the event of a technical problem in Windows, the support is provided by the PC manufacturer or the license reseller and not by Microsoft.

Volume License (VL)

Microsoft sells volume license key (VLK or Volume Licensing Key) for organizations and companies who need to install and activate Windows on multiple machines simultaneously.

What is the interest of a volume license?

To understand, we put ourselves in the place of an administrator: we must install an identical copy of Windows on all machines in our computer and in addition activate Windows on each of these machines. To save time, it would be good to have an automatic deployment tool to install and activate this identical copy of Windows – configured according to the strategy of the company – from our server on all client computers. The Windows Deployment Services (WDS or Windows Deployment Services) precisely to meet this need. Thanks to the WDS, the administrator will be able to deploy an identical image (or copy) of Windows  on all the client computers!

How to obtain this license in volume?

First, the administrator must purchase an OEM or Retail Windows license for his server . This is a mandatory step. Unfortunately, with an OEM or Retail license, the administrator does not have the right to create an image (or copy) of Windows, it is written in the license of use. It is therefore impossible to use Windows Deployment Services (WDS) to deploy our Windows image on all client computers. A  volume license allows however to use the WDS!

To obtain this license in volume, the administrator will have to update his existing OEM or Retail license, as we do when we want to go from Windows 10 Family to Windows 10 Pro via the Windows Store for example. A volume license is therefore an upgrade of an OEM or Retail license , with additional rights to create and deploy system images .

How is the activation of Windows on the client computers?

With a volume license , client computers do not need to activate Windows over the internet or over the phone. Instead, the administrator can use a local activation service within his network called the  Key Management Service (KMS) . The KMS is  required to activate more than 25 machines on its network. By choosing KMS activation , the administrator installs a  KMS service on the server. Therefore, it is he who will serve as an activation server for client computers: it replaces the Microsoft activation server that we – individuals – use to activate Windows. All machines activated via the KMS service must be reactivated periodically twice a year, every 180 days.

If the administrator wants to activate less than 25 machines, he can choose multiple activation key (MAK key)  instead of KMS service: each computer then connects separately and at once to the Microsoft activation server to activate Windows .

How it works ?

By purchasing a volume license , the administrator will have access to a special ISO image of Windows. This special ISO contains a version of Windows that does not need a product key. It is this ISO image that will be deployed on client computers.

The administrator will also have access to a special product key: a KMS product key ,  allowing him to activate the KMS server . Only one activation is required from Microsoft: once the KMS server is activated, there will be nomore communication between the client computers and the KMS server on one side, and Microsoft on the other side. The administrator then deploys his ISO image of Windows on all client computers. Once a client is installed, it scans the network for the KMS server and activates it. Once activated, customers have a valid Windows license as long as the activation is renewed twice a year (180 days) with the KMS service .

The digital license activation method

At the release of Windows 10, a new activation method has emerged: the digital license (called “digital right” in Windows 10 version 1511). Unlike the traditional activation method where you enter a product key to activate Windows, here the activation of Windows is done only by internet and avoids having to enter a product key.

Also Read: Transfer your Windows license to another PC

digital license of Windows 10 will be assigned to your PC in the following cases:

  • By  upgrading to Windows 10  for free from  a genuine copy of Windows 7 or Windows 8.1 (this offer is no longer available)
  • By upgrading to Windows 10 ( version 1511 or later) and after activating your copy of Windows 10 using a Windows 7, Windows 8, or Windows 8.1 product key
  • By buying a genuine copy of Windows 10 in the Windows Store and after activating your copy of Windows 10
  • By purchasing an upgrade to Windows 10 Pro in the Windows Store and after activating your copy of Windows 10
  • By being Windows Insider and by upgrading to Windows 10 Insider Preview for free from an authentic copy of Windows 7 or Windows 8.1, or from  Windows 10 Preview (this offer is no longer available)

How does the digital license activation process work ?

It’s simple: after the first installation of Windows 10 and the first activation of Windows, a  unique identification code is generated to identify your machine (desktop PC, laptop, tablet, etc.). To create this unique code, Microsoft relies on all your hardware configuration (motherboard, hard disk, processor …). Thanks to him,  Microsoft gives your machine  a digital license of Windows 10in its database. If you redo a clean installation of Windows 10 on your PC, when Windows is activated, Microsoft will look for the unique identification code of your machine and will check if it is linked to a digital license of Windows 10 or not . If so, Windows 10 will be activated. As this unique identification code is stored on Microsoft servers, activation is done exclusively via the internet .

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What happens if I change my  hardware configuration ?

There are two scenarios:

  1. If you have a Retail license for Windows 10 (having purchased directly from Windows 10 in a box or via the Windows Store, having made the free upgrade to Windows 10 from a retail license of Windows 7 / 8.1 or by activating Windows 10 with a Windows 7 / 8.1 product key in Retail version), your Windows will certainly not be activated any more but it is enough to restart the activation process so that it is again.
  2. If you have an OEM license for Windows 10 (having purchased a PC pre-installed with Windows 10 or having made the free upgrade to Windows 10 from a Windows 7 / 8.1 OEM license): as your Windows 10 license is linked to your unique identification code that is based on all of your current hardware configuration, if you change an essential component of your configuration (motherboard or hard drive), Windows 10 will no longer be activated . By modifying a component of your system, you will obtain a new identification code  which is not related to your Windows 10 license. To reactivate Windows 10, you will have to contact  Microsoft Customer Support .

Windows Licensing FAQ

I have no or no Windows installation support (USB key or DVD installation), the manufacturer of my PC did not provide me: how to do if I want to reinstall Windows?

Many solutions :

  • Use the manufacturer-installed recovery partition on the hard drive to do a PC factory restore
  • Create a recovery DVD or USB key using the software installed by the manufacturer in Windows. This will also allow you to do a factory restore of the PC
  • Create your own Windows installation DVD or USB key (click here to learnHow to create and  install Windows 7 on a PC with USB 3.1.

Quickly, what are the differences between a Retail license and an OEM license?

OEM licenses for Windows are identical to Retail licenses except for the following:

  • OEM licenses do not offer support from Microsoft, with the assistance of Microsoft technicians. In case of technical problems with Windows, you must turn to the support of the manufacturer of your computer
  • OEM licenses are permanently attached to the very first PC on which Windows is installed and enabled
  • OEM licenses allow the update of any hardware component, except for a different motherboard and hard drive model
  • OEM licenses can not be used directly to update an older version of Windows

I have the 32-bit version of Windows that is installed on my PC. Can I reinstall Windows in 64-bit version?

An OEM license can be used to install a 32-bit or 64-bit version of Windows. If you purchased a pre-installed PC with a 32-bit version of Windows Family, you can reinstall Windows 10 Family in its 64-bit version. The license agreement grants the right to install your Windows version regardless of its 32-bit or 64-bit version.

Can I resell the product key of an OEM license?

No ! You will have to resell the entire PC and not just the license, since the license is related to PC life.

What license do I get after doing the free update to Windows 10?

You keep the same license as you had on your previous version of Windows (Windows 7 or Windows 8.1). If you had an OEM license for Windows 7 / 8.1, you get an OEM license for Windows 10; if you had a Retail license for Windows 7 / 8.1, you get a Windows 10 Retail license that you can freely transfer to any PC.

Can I activate my OEM license using a Windows installation DVD or USB key from an ISO that I downloaded from the internet?

Yes !

How do I know if I have an OEM license or a Retail license?

Simultaneously press the keys Windows + Pause to open the Control Panel System Panel. Scroll down the screen and locate the product ID line .

The product ID should be in the form xxxxx-xxx-xxxxxxx-xxxxx. Locate the 3 characters of the second group: if these 3 characters are “OEM”, then you have a Windows OEM license .

Can I downgrade my version of Windows to an earlier version?

Yes, OEM licenses for some versions of Windows are eligible for demotion :

  • Windows 10 Professional Downgrades to Windows 8.1 Professional or Windows 7 Professional
  • Windows 8.1 Professional Downgrades to Windows 7 Professional or Windows Vista Business
  • Windows 7 Professional and Windows 7 Ultimate  Downgrade to Windows Vista Business, Windows Vista Ultimate, Windows XP Professional, Windows XP Tablet PC Edition, or Windows XP x64 Edition

For more information about downgrading a version of Windows :

I want to buy three PCs, how many Windows license should I buy?

A Windows license can be used on one PC at a time, regardless of the type of license (OEM or Retail). Remember this: 1 PC = 1 license, 2 PC = 2 licenses, 3 … Do you really want me to continue??

Do I really have to activate Windows?

Windows activation is mandatory except for PCs purchased from a major brand manufacturer (Asus, Lenovo, Packard Bell …) who have pre-activated OEM licenses, and volume licenses (VL). You have 30 days to activate Windows via internet or phone after installing Windows. You can activate Windows as many times as you want: the activation number on the internet is limited, unlike the phone activation which is unlimited.

Can I use my product key on multiple PCs at the same time?

No, the terms of the license state that the product key can only be used on one PC at a time.

I intend to change the hardware configuration of my PC, will I have to reactivate Windows? Will my license still be valid?

If you have a Retail license , after upgrading your hardware configuration, you will simply have to restart the activation process to activate Windows. If you have an OEM license on the other hand, it is more complicated: if you change an essential hardware component (such as the motherboard or the hard disk), Windows will no longer be activated. If you restart the activation process, you will get an error message. To reactivate Windows, you will need to contact the technical support of the manufacturer of your computer or Microsoft support .