Windows Server
About Windows Server
Windows Server 2025 is the operating system that bridges on-premises environments with Azure services, enabling hybrid scenarios that maximize existing investments.
- Increase security and reduce business risk with multiple layers of protection built into the operating system.
- Evolve your datacenter infrastructure to achieve greater efficiency and scale with Hyper Converged Infrastructure.
- Enable developers and IT pros to create cloud native applications and modernize their traditional apps using containers and micro-services.
Choose from three primary editions of Windows Server, based on the size of your organization as well as virtualization and datacenter requirements:
- Datacenter: Azure Edition helps you use the benefits of the cloud. The edition includes hotpatch, and is available on Azure only.
- Datacenter edition is ideal for highly virtualized and software-defined datacenter environments. It includes software-defined datacenter (SDDC) features in the host, unlimited Windows Server containers with and without Hyper-V isolation, and unlimited virtualization1. Datacenter edition is licensed under the Per Core/CAL2 license model and requires a Windows Server CAL for access to the server.
- Standard edition is ideal for customers with low density or non-virtualized environments, and includes unlimited Windows Server containers without Hyper-V isolation and two Windows Server containers with Hyper-V isolation. Standard edition is licensed under the Per Core/CAL2 license model and requires a Windows Server CAL for access to the server.
Windows Server 2025 also offers a new cloud billing option, providing pay-as-you-go flexibility across on-premises and cloud environments, allowing for scalable expansion with additional VMs. To learn more about how to use pay-as-you-go licensing, please see here: Configure Windows Server Pay-as-you-go with Azure Arc
1 This does not apply to pay-as-you-go subscription.
2 For more details about the Per Core/CAL license model, please see the licensing brief, Introduction to Microsoft Core licensing.
Pricing
Compare features
Licensing guide
Flexible Virtualization Benefit guide
Feature comparison
Windows Server offers additional features in the Standard and Datacenter editions. Features exclusive to the Windows Server Datacenter edition include Shielded Virtual Machines, software-defined networking, Storage Spaces Direct, and Storage Replica. Windows Server also includes features like unlimited Windows Server containers.
Feature/Right
|
Standard edition
|
Datacenter edition
|
||
---|---|---|---|---|
Core Windows Server functionality |
✓
|
✓
|
||
Hybrid integration |
✓
|
✓
|
||
Hyper Converged Infrastructure |
Unlimited
|
|||
OSEs/Windows Server Containers with Hyper-V isolation1 |
Two
|
Unlimited
|
||
Windows Server Containers without Hyper-V isolation |
Unlimited
|
✓
|
||
Host Guardian Service |
✓
|
✓
|
||
Storage Replica2 |
✓
|
✓
|
||
Shielded virtual machines (VMs) |
✓
|
|||
Software-defined networking |
✓
|
|||
Software-defined storage |
✓
|
1 This does not apply to pay-as-you-go subscription.
2 Windows Server Standard edition license limited to single Storage Replica volume up to 2TB.
FAQ
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Core licenses are sold in packs of two (each pack contains two licenses), and packs of 16 (each pack contains 16 licenses).
- When licensing is based on physical cores, each processor needs to be licensed with a minimum of eight core licenses. Each physical server, including single-processor servers, needs to be licensed with a minimum of 16 core licenses. One core license must be assigned for each physical core on the server. Additional cores can then be licensed in increments of two or 16.
- When licensing by virtual machine, one license must be assigned for each virtual core allocated to the virtual machine, subject to a minimum of eight licenses per virtual machine. Licensing by virtual machine requires subscription licenses or licenses with Software Assurance.
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Windows Server Standard and Datacenter editions continue to require Windows Server CALs for every user or device accessing a server (see the Product Terms for exceptions), or Windows Server External Connector licenses for servers accessed by external users. In addition to the base Windows Server CAL or External Connector license, some functionalities require the purchase of an Additive Access License. Examples of additional or advanced functionalities include Remote Desktop Services or Active Directory Rights Management Services. A pay-as-you-go subscription does not require CALs; however, Remote Desktop Services (RDS) CALs are still required.
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The Azure Hybrid Benefit lets you redeploying your on-premises Windows Server subscription licenses or licenses with Software Assurance to Azure. Rather than paying the full price for a new Windows Server virtual machine, the Azure Hybrid Benefit will apply a discount to the base compute rate.
Each set of 16 Windows Server core licenses with Software Assurance entitles you to use Windows Server on Microsoft Azure on up to 16 virtual cores allocated across two or fewer Azure virtual machines. Each additional set of eight entitles use on up to eight virtual cores and one Base Instance. In other words, once a minimum initial allocation of 16 eligible licenses is made, you can add virtual cores (up to eight) to an existing or new virtual machine with incremental sets of eight eligible licenses. Each incremental set of eight licenses must be allocated to a single virtual machine.
With Azure Hybrid Benefit, you can move or add incremental workloads into Azure and pay non-Windows (Linux) pricing. With Datacenter Edition licensing, you get these lower-cost instances in Azure while maintaining existing on-premises deployments. This is referred to as dual use rights. Standard Edition licensing provides lower-cost instances in Azure, but does not provide dual use rights.
Use of Windows Server on Azure is subject to Azure Services in the Product Terms site. This means access to base Windows Server functionality on Azure does not require base Windows Server CALs, and you can leverage the Azure hosting clause to host your own customer solutions.
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Under the Flexible Virtualization Benefit, you can deploy your Windows Server subscription licenses or licenses with active Software Assurance to any Authorized Outsourcers’ servers (shared or dedicated). The same terms that govern use on-premises apply. This option is not available on Listed Providers’ clouds. License Mobility through Software Assurance, Microsoft’s legacy License Mobility option that allows customers to move some server application licenses to authorized public clouds, is not available for Windows Server. As an alternative to deploying your own licenses under the Flexible Virtualization Benefit, you may use Windows Server on other public clouds via infrastructure as a service (IaaS) offerings through authorized Service Providers.
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In order to provide customers with a variety of options to license Windows Server, Microsoft makes licenses for Windows Server available to Service Providers for access by end customers as part of Service Provider solutions. This is done through an agreement between Microsoft and Service Providers. Pricing for these Windows Server services offered by the Service Provider is set by the Service Provider.
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Two new sets of rights were introduced in October 2022 for customers with subscription licenses or licenses with active Software Assurance. These are the Flexible Virtualization Benefit and the option to license Windows Server Datacenter and Standard by virtual machine.
- The Flexible Virtualization Benefit is an extension of Outsourcing Software Management rights. It allows you to deploy eligible licenses to any Authorized Outsourcers’ servers (shared or dedicated). This benefit applies broadly across software products. Previously, the only option to deploy your Windows Server licenses in third party data centers was to use Authorized Outsourcers’ dedicated servers.
- When you license Windows Server by virtual machine, as an alternative to fully licensing a server based on physical cores, you need only a number of licenses equal to the virtual cores allocated to your virtual machine (subject to a minimum of eight per virtual machine). You can also move licenses between servers within the same Server Farm at any time as needed.
Licensing by virtual machine and deploying to an Authorized Outsourcer’s shared servers may be a cost-effective option for moving your workloads to the cloud.