Windows Server 2022 Datacenter core add-on

What is included in Windows Server 2022 Datacenter core add-on?

Additional cores – Licenses physical cores beyond the base 16.
Same edition – Extends an existing Datacenter base license only.
No media – Uses the base license key and installer.
Unlimited VMs – Keeps Datacenter rights to run unlimited OSEs.
Datacenter features – Storage Spaces Direct, Shielded VMs, software-defined networking.
Important – This add-on contains no product key, no installer, and no Client Access Licenses (CALs).

What are the main benefits of Windows Server 2022 Datacenter core add-on?

The Datacenter core add-on is an Additional License pack that licenses extra physical cores on a server that already runs a Windows Server 2022 Datacenter base license. It exists for hardware with more than 16 cores, where every physical core must be covered for the installation to stay compliant.

Full core coverage – Licenses all cores on high-density servers.
Compliance fix – Closes the gap on 24, 32, 64-core hosts.
No re-install – Adds cores without touching the running system.
Cost control – Buy only the extra cores you need.
Edition match – Preserves unlimited virtualization on the host.
Pack flexibility – Sold in 2, 4, and 16-core increments.

What does the Datacenter core add-on actually do?

It licenses additional physical processor cores on a server that already has a Windows Server 2022 Datacenter base license. Windows Server 2022 is licensed per physical core, and a base license covers 16 cores; any server with more cores than that must be fully covered, or the installation is under-licensed. The add-on supplies that extra coverage without changing the operating system already installed. It carries no installer and no product key, so it has no effect on its own and only takes effect when paired with a matching Datacenter base license.

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Can I install a server using only the core add-on?

No. The core add-on ships with no media and no product key, and it relies on the installer and key from the Datacenter base license. On its own it cannot activate or boot a server, which is the most common buying mistake with this product. If you do not already own a Windows Server 2022 Datacenter base license, buy that first and add the core packs afterward. Buying add-on cores without a base license leaves you with a pack that cannot be installed.

How many cores do I need to license, and in what packs?

Every physical core in the server must be licensed, with a minimum of 8 cores per processor and 16 cores per server. The 16-core base license covers the minimum; the add-on covers the remainder, so a 24-core server needs 8 extra core licenses and a 32-core server needs 16. Core licenses are sold in packs of 2, 4, and 16, letting you match the exact core count of your CPUs. Count the physical cores per socket before ordering, since under-licensing by even two cores breaks compliance.

Does the core add-on include Client Access Licenses (CALs)?

No. Core licenses, including this add-on, never include CALs, which are required separately for every user or device that connects to the server. A CAL is not software; it is the legal right for a user or device to use server services such as file shares, printing, or authentication. Windows Server 2022 CALs are sold as User CALs or Device CALs, and you choose based on whether you have more users or more shared devices. Plan the CAL count alongside the core count so the deployment is fully covered.

What does the Datacenter edition give me that Standard does not?

Datacenter grants unlimited virtual machines (OSEs) on a fully licensed host, while Standard is limited to two per set of core licenses. Datacenter also unlocks Storage Spaces Direct, Shielded Virtual Machines, software-defined networking, and unlimited Storage Replica, none of which are available in Standard. These features matter for clustered hyper-converged storage and dense virtualization, where Standard would force you to repeatedly re-license the same hardware to add VMs. The core add-on preserves these Datacenter rights as you scale up to higher core counts on the same host.

What should I check before choosing this core add-on?

Confirm three things: that you already own a Windows Server 2022 Datacenter base license, that the add-on edition matches that base exactly, and that the total core licenses equal every physical core in the server. A Datacenter add-on extends a Datacenter base only; it cannot top up a Standard installation. Hotpatching, which lets you apply updates without rebooting, is not part of on-premises Datacenter 2022 and is reserved for the Azure Edition, so do not assume it is included. Verifying the base edition and exact core count before buying prevents the most frequent reason these packs cannot be activated.

Legal Information About Our Products

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Below you will find the most important legal information about our products.

Unused and Non-Activated Product Keys

We offer exclusively unused and non-activated product keys. The keys have never been redeemed for activation and are fully available to the purchaser for the first-time activation of the respective product. A key that has already been redeemed could no longer be used for a new activation and is therefore not offered by us.

Trading in these product keys is permissible in the European Union and in Switzerland under current case law, provided that the necessary conditions are met. These conditions are as follows:

• The software must originally have been placed on the market with the consent of the rightholder within the territory of the EU, another contracting state of the EEA, or Switzerland by way of sale.
• The license for the software must have been granted in return for the payment of a fee intended to enable the rightholder to obtain remuneration corresponding to the economic value of the copy of the software.
• The rightholder must have granted the first acquirer the right to use the software permanently (for an unlimited period).
• Any improvements and updates that the subsequently downloaded computer program has compared to the originally downloaded one must be covered by a maintenance agreement concluded between the rightholder and the first acquirer.
• The original licensee must have made their own copies unusable.

This trade is legally permissible because the underlying license was already placed on the market with the consent of the rightholder within the EU/EEA or Switzerland in return for appropriate remuneration. As a result, the so-called principle of exhaustion has taken effect, which permits the resale of individual product keys — in particular those originating from volume license agreements. Microsoft or the respective software provider has already received appropriate remuneration for this.

keys.express and keys.discount ensure that the aforementioned conditions are met and that the lawful use of the software is guaranteed. The requirements arising from European legislation are also observed in Switzerland.

Important note: The acquisition of a product key through the transmission of a combination of numbers and letters in digital form does not, in itself, constitute a license for the lawful use of the program. The license only arises from the respective installation and the associated acceptance of the manufacturer's terms of use.

Further information can be found here:

• Legal assessment by Swiss lawyers

Overview of the Most Important Legal Information

• We offer unused, non-activated product keys for the activation of the respective computer programs. The key alone is not yet a license.
• The license only arises from the respective installation and the resulting acceptance of the terms of use. These terms of use govern the right to use the software between you and the respective manufacturer.
• The principle of exhaustion has, as a rule, taken effect — i.e. the license is "used up" — as soon as it was lawfully placed on the market for the first time. The products concerned are software placed on the market for unlimited-time use in the form of an activatable product key with the option to download the program. Microsoft or the respective software provider has received appropriate remuneration for this.
• You gain access to particularly attractively priced product keys from volume license agreements, which are to be treated legally in the same way as parts of volume licenses upon first acquisition.
• The software itself is always the same original software that is also obtained through official download channels or manufacturer sources. You are therefore not paying for a different or inferior version, but for a valid activation key or a corresponding license.
• All brand names and brand logos are registered trademarks, whose use here serves solely for product description — the ownership rights lie with the respective trademark holder.