Windows Server 2025: the most important new features

What is new in Windows Server 2025? Windows Server 2025 has been available since November 1, 2024 and receives security updates until November 14, 2034. The most important new features: hotpatching via Azure Arc, SMB over QUIC also in Standard and Datacenter, stricter security defaults for SMB and Active Directory, GPU partitioning for virtual machines and the direct in-place upgrade from Windows Server 2012 R2. The licensing model by cores with CALs remains unchanged.

Quick decision

If you …	this is new for you
want to patch servers without a restart	hotpatching via Azure Arc
run file servers for branch offices and working from home	SMB over QUIC in Standard and Datacenter
secure an old Active Directory	LDAP encryption, 32k database pages, new service accounts
run virtual machines with a graphics card	GPU partitioning
come from 2012 R2 or 2016	direct in-place upgrade
manage local administrator accounts	extended features of Windows LAPS

Key data

Feature	Windows Server 2025
Available since	November 1, 2024
End of mainstream support	November 13, 2029
End of extended support	November 14, 2034
Editions	Standard, Datacenter, Datacenter: Azure Edition, Essentials
Licensing model for Standard and Datacenter	core licenses and CALs, at least 16 core licenses per server
Minimum processor	64 bit, 1.4 GHz, plus SSE4.2 and POPCNT
Minimum memory	2 GB, 4 GB recommended with Desktop Experience
Minimum disk space	32 GB

Security

Hotpatching. Security updates can be installed without restarting the server. Until now this was only available in the Datacenter: Azure Edition. In Windows Server 2025 it is available for Standard and Datacenter if the server is connected to Azure Arc. Microsoft’s edition comparison lists hotpatching as a service via Azure Arc with separate billing.

Credential Guard. The protection for credentials is enabled by default on devices that meet the requirements.

SMB. Several defaults have become stricter:

New feature	Effect
SMB signing	required by default for all outbound connections, previously only for SYSVOL and NETLOGON
Limit on sign-in attempts	slows down attacks that try out passwords
NTLM blocking in the SMB client	NTLM can be blocked for outbound connections
Alternative ports	the SMB client can use ports other than the default ports
Auditing	logs remote ends that do not support signing or encryption

The enforced signing can affect older network storage devices and multifunction devices that cannot handle SMB signing. Test such devices before the changeover.

OpenSSH. The OpenSSH server is preinstalled and can be turned on in Server Manager. Previously it had to be installed afterwards.

Windows LAPS. The management of local administrator passwords can create accounts automatically, detects restored system images and, if desired, generates easily readable passphrases.

Active Directory

32k database pages. New domain controllers can use a database with 32k pages. This removes limits of the previous 8k pages. The feature is optional and requires the new functional level.
New functional level. Windows Server 2025 comes with a new domain and forest functional level.
LDAP. New environments encrypt LDAP connections after sign-in by default. LDAP over TLS supports TLS 1.3.
Delegated Managed Service Accounts. A new account type with which conventional service accounts can be converted to managed accounts with automatically generated keys.

If you add a domain controller with Windows Server 2025, you need version 2025 CALs for all users, see Which CAL version fits which server.

File services and storage

SMB over QUIC connects clients to the file server in encrypted form, even over untrusted networks such as the internet. Until now the server feature was only available in the Datacenter: Azure Edition; now it is included in Standard and Datacenter. Access can be restricted to specific clients.
NVMe. Microsoft states higher performance with NVMe storage at lower processor load.
ReFS supports deduplication and compression directly in the file system.
Storage Replica can compress the transfer.
Storage Spaces Direct (Datacenter only) supports thinly provisioned storage.

Hyper-V and virtualization

New feature	Detail
GPU partitioning	one graphics card is shared among several VMs; in Standard for standalone servers, in a cluster with Datacenter
Scaling of the host	up to 4 petabytes of memory and 2,048 logical processors
Scaling of the VM (generation 2)	up to 240 TB of memory and 2,048 virtual processors
Workgroup clusters	Hyper-V clusters without an Active Directory domain, with live migration
Network ATC	network configuration for clusters by intent instead of individual steps

Nothing has changed in the virtualization rights: two virtual machines per round of licensing with Standard, an unlimited number with Datacenter. The rules are in
Licensing Windows Server and virtualization correctly.

Operation and upgrade

Interface. The Desktop Experience looks like Windows 11.
Bluetooth. Mouse, keyboard and headset can be connected via Bluetooth.
In-place upgrade across four versions. Windows Server 2025 can be installed directly from Windows Server 2012 R2, 2016, 2019 and 2022. With earlier versions, at most two version steps were possible. In a failover cluster, still only one step is possible.
Tools. Windows Terminal and the WinGet package manager are on board, as is the DTrace diagnostic tool.

Every version also removes features or stops developing them. Microsoft keeps a separate list of these. Check it if you use older roles or scripts.

Licensing: what stays the same, what is new

The core counting (all physical cores, at least 8 per processor and 16 per server), the VM rights and the CAL requirement have stayed the same. A server with two processors of 8 cores each needs 16 core licenses on 2025 as on 2022, and 32 with four VMs on Standard.

New is usage-based billing via Azure Arc as an alternative to the perpetual license. According to Microsoft, Windows Server CALs are not needed with it, while RDS CALs remain necessary.

To note when moving: CALs and RDS CALs of earlier versions are not valid for Windows Server 2025. The licensing model is explained in
Licensing Windows Server: cores, VMs, CALs; the
license calculator works out the quantities for your server.

Typical cases

Office with an old 2016 server. End of support for 2016 is January 12, 2027. The move to 2025 brings eight years of security updates. New server licenses and 2025 CALs are needed.

File server for field staff and working from home. SMB over QUIC allows encrypted access to shares over the internet. On 2022 this would have required the Azure Edition; with 2025, Standard is enough.

Line-of-business application not yet certified. Then 2022 stays for the time being, see
Windows Server 2025 or 2022.

Business with many restart windows on weekends. Hotpatching reduces the number of restarts. Weigh the cost of the Azure Arc service against the effort of the maintenance windows.

At VivaKeys

All offers are in the categories
Windows Server and
CALs. Which edition fits is clarified in
Windows Server 2025 Standard or Datacenter.

Frequently asked questions

When was Windows Server 2025 released? Microsoft gives November 1, 2024 as the start of the lifecycle.

How long is Windows Server 2025 supported? Mainstream support ends on November 13, 2029, extended support with security updates on November 14, 2034.

Which editions of Windows Server 2025 are there? Standard, Datacenter, Datacenter: Azure Edition and Essentials. For your own servers, Standard and Datacenter come into question, for very small businesses Essentials.

Where do I get the ISO file for Windows Server 2025? You download the installation file from the publisher or via the link in our delivery email. The product key is entered during installation or afterwards.

Can I convert an evaluation version of Windows Server 2025 to a full version? Yes, Microsoft describes the conversion with a product key. Exception: a domain controller cannot be converted from the evaluation version to the full version.

Do I need new CALs for Windows Server 2025? Yes. CALs of earlier versions are not valid for Windows Server 2025. You need Windows Server CALs 2025 and, for Remote Desktop, RDS CALs 2025.

Does Windows Server 2025 run on older hardware? In addition to the previous requirements, the processor must support SSE4.2 and POPCNT. Very old server CPUs are therefore ruled out.

Sources

Checked on 2026-11-10 against the publisher’s information: