Microsoft Windows Server 2025 Datacenter

Windows Server 2025 Datacenter: server operating system for highly virtualised environments

Windows Server 2025 Datacenter is the edition of the current Windows Server generation that Microsoft intends for highly virtualised data centres and cloud environments. If all processor cores of a server are licensed, any number of virtual machines running Windows Server may be operated on it. In addition, there are features for software-defined storage, software-defined networking and shielded virtual machines. The edition is therefore aimed at businesses and service providers that consolidate many server instances on a few hosts or operate Hyper-V clusters.

Licensing and virtualisation

Windows Server 2025 Datacenter is licensed per processor core. Under Microsoft's licensing rules, all physical cores of the server must be licensed, but at least 8 cores per processor and 16 cores per server. If all cores are licensed, Datacenter allows an unlimited number of virtual operating system environments as well as unlimited Windows Server containers and Hyper-V isolated containers on this server. A host with 32 cores can thus run, for example, domain controllers, database servers, terminal servers and test systems as separate virtual machines without additional server licences being required for further instances. Every user or device that accesses the server requires a Windows Server CAL; for Remote Desktop Services, an RDS CAL is also required.

With Automatic Virtual Machine Activation, guest systems running Windows Server are activated automatically on an activated Datacenter host. This simplifies deployment when new virtual machines are created regularly.

Features of the Datacenter edition

Storage Spaces Direct combines the local drives of several servers into shared, software-defined storage for a cluster. In Windows Server 2025, volumes can also be thin provisioned: storage is only allocated from the pool when needed. Storage Replica replicates volumes between servers or sites without any limit on partnerships and now supports compression of replication traffic.

For software-defined networking, Datacenter includes the Network Controller, which runs as a cluster role in Windows Server 2025. New features are tag-based segmentation, which allows network policies to be defined via Windows Admin Center, and SDN Multisite for connections between two sites. Hyper-V support for the Host Guardian Service allows shielded virtual machines to be operated on guarded Hyper-V hosts.

GPU partitioning divides one graphics card proportionally among several virtual machines, with support for high availability and live migration. According to Microsoft, Datacenter is required for unplanned failures in the cluster.

New in Windows Server 2025

Several protection features are enabled out of the box: Credential Guard for protecting credentials is active on suitable devices, and outbound SMB connections require signing by default. SMB over QUIC establishes encrypted connections to file shares over the internet. For Active Directory, there are new functional levels, an optional database format with 32k pages and TLS 1.3 for LDAP. Hyper-V supports up to 4 PB of RAM and 2,048 logical processors per host. The Desktop Experience is based on Windows 11, OpenSSH Server and WinGet are preinstalled, and a direct upgrade is possible from Windows Server 2012 R2 across up to four versions.

Buy Windows Server 2025 Datacenter: licence and scope of delivery

You receive a product key to activate Windows Server 2025 Datacenter. You select the number of core licences in the product variant when ordering. No specific number of cores is stated on the product page; the licence requirement depends on the number of physical cores in your server, at least 16 per server. Windows Server CALs and RDS CALs are not part of this offer. The scope of delivery includes:

• the product key for Microsoft Windows Server 2025 Datacenter
• the download link for the server software (all downloads are also available under Software Download)
• instructions for installation and activation (see also Guides and FAQ)
• the invoice by email

Once your payment has been received, your product key is displayed directly on the order confirmation page and also sent to you by email. After that, you can retrieve it again at any time: with a customer account under My Product Codes, without a customer account via the Guest Portal.

If you have any questions about installation or activation, our Support team is available around the clock by email. You will find offers for businesses, schools and public authorities in the B2B Area. You will find further server products in the category Windows Server and under Operating Systems.

System requirements

Minimum requirements according to Microsoft. They apply to the Server Core and Desktop Experience installation options. For Secured-core servers, Microsoft additionally requires IOMMU (Intel VT-d or AMD-Vi), Kernel DMA Protection, DRTM, TPM 2.0, Secure Boot and virtualisation-based security.