Windows Server 2019 Datacenter

Windows Server 2019 Datacenter is the edition of Microsoft's server operating system built for heavily virtualised hosts and software-defined datacentres. You choose the number of cores at checkout to match your server, and with every core licensed you can run unlimited virtual machines on the host. You get the key by email after payment, with download and activation instructions.

• Core count selectable at checkout to match your server
• Unlimited virtual machines (OSEs) when all cores on the host are licensed
• Users and devices need Windows Server 2019 CALs, sold separately
• Digital delivery: nothing is shipped

How many core licences does my Windows Server 2019 Datacenter server need?

Count every physical core in the server, then apply Microsoft's minimums: at least 8 core licences per processor and at least 16 per server. Choose the core count at checkout to match that total.

The licence counts physical cores, not threads, so hyper-threading doesn't change the number you need.

Server	Physical cores	Core licences needed
1 processor, 4 cores	4	16
1 processor, 16 cores	16	16
2 processors, 6 cores each	12	16
2 processors, 12 cores each	24	24
2 processors, 16 cores each	32	32

To check your server, open Task Manager and look at Performance → CPU, which shows sockets and cores.

Do I need Windows Server 2019 Datacenter, or is Standard enough?

Datacenter makes sense when you run more than a few virtual machines on one host, or need Storage Spaces Direct and software-defined networking. Both editions share the same core operating system. The differences are virtualisation rights and some advanced datacentre features.

	Standard	Datacenter
Virtual machines per licensed host	2	Unlimited
Hyper-V	Yes	Yes
Storage Spaces Direct	No	Yes
Software-defined networking (Network Controller)	No	Yes
Host Guardian Hyper-V support (shielded VMs)	No	Yes
Best for	Small offices, single servers, up to 2 VMs	Heavily virtualised hosts and clusters

With Datacenter, once every physical core is licensed, you can run as many Windows Server VMs on that host as the hardware allows. Beyond a handful of VMs per host, stacking Standard licences usually costs more than Datacenter.

Do I need CALs with Windows Server 2019 Datacenter?

Usually, yes. Microsoft's licensing terms require a Windows Server CAL (client access licence) for each user or device that accesses the server, and CALs are sold separately from core licences.

User CALs cover one person on any number of devices; Device CALs cover one device, whoever uses it. People who connect through Remote Desktop Services also need an RDS CAL. CALs must be the same version as the server or newer, so Windows Server 2019 CALs cover 2019 and earlier.

What's new in Windows Server 2019, and how long is it supported?

Windows Server 2019 added Windows Admin Center support, System Insights, Storage Migration Service and Linux containers on Windows. Today it is mainly chosen where an application or an existing environment requires this version.

Mainstream support for Windows Server 2019 ended on 9 January 2024. It still receives security updates under extended support until 9 January 2029, but no new features. For new deployments, Windows Server 2025 is supported for much longer.

What are the system requirements for Windows Server 2019?

You need a 1.4 GHz 64-bit processor, at least 1 GB of RAM for Server Core (2 GB with the Desktop Experience) and 32 GB of storage. These are bare minimums; real workloads need far more memory and disk.

Component	Minimum requirement
Processor	1.4 GHz 64-bit (x64), with NX/DEP and SLAT support
Memory (RAM)	1 GB (Server Core); 2 GB (Desktop Experience); ECC memory for physical hosts
Storage	32 GB or more on a PCI Express storage adapter
Network	Gigabit (1 Gbps) Ethernet adapter
Firmware and security	UEFI with Secure Boot and TPM 2.0 for features such as BitLocker

See Microsoft's full Windows Server hardware requirements.

How do I activate Windows Server 2019 Datacenter?

Install Windows Server 2019 Datacenter from the download link in your order email. Then enter your product key in Settings, or with a command if you use Server Core. Make sure you installed the Datacenter edition: a Datacenter key won't activate a Standard or Evaluation install directly.

1. Install Windows Server 2019 Datacenter (Desktop Experience or Server Core).
2. With Desktop Experience: open Settings → Update & Security → Activation → Change product key and enter your key.
3. With Server Core: run slmgr /ipk YOUR-PRODUCT-KEY, then slmgr /ato.
4. Check activation with slmgr /xpr, or under Activation in Settings.

A common issue we see is a key entered on an Evaluation install. Settings may reject it; convert the edition with DISM first, as described in the FAQ below.

Frequently asked questions

Which core count should I select?

Select the total number of physical cores in your server, with a minimum of 16. For example, a server with two 10-core processors needs 20 core licences. If you add processors later, you can cover the extra cores with a core add-on licence.

How many virtual machines can I run with Windows Server 2019 Datacenter?

As many as your hardware can handle, once all physical cores on the host are licensed. That covers every Windows Server VM on that host, which is why Datacenter suits virtualisation hosts and clusters. Users of those VMs still need CALs.

Can I use older CALs with Windows Server 2019?

No. CALs must be the same version as the server or newer. Windows Server 2019 CALs also cover access to Windows Server 2016, but older CALs don't cover a Windows Server 2019 server. The same rule applies to RDS CALs used for Remote Desktop sessions.

Can I upgrade from the Evaluation edition?

Yes. Convert a Windows Server 2019 Evaluation install with DISM /online /Set-Edition:ServerDatacenter /ProductKey:YOUR-KEY /AcceptEula, then restart. Your roles and data stay in place. Microsoft notes that this doesn't work on a domain controller.

See all Windows Server 2019 licences and CALs, or compare with the newer Windows Server 2025.