How to Download, Install and Activate Windows Server 2016, 2019, 2022 and 2025

Windows Server installs are straightforward once you know three things: which ISO to use, which edition and installation option to pick during setup, and how activation works on a server compared with a desktop. This guide covers all three for Windows Server 2016, 2019, 2022 and 2025, from a blank machine or virtual machine to a server that reports “Windows is activated”. It applies to the licences in our Windows Server category, each of which ships with the official download link.

Hardware and virtual machine requirements

Windows Server 2025 requires a 64-bit processor at 1.4 GHz with support for the x64 instruction set, SSE4.2 and POPCNT, 2 GB of RAM for Server Core or 4 GB for Desktop Experience, 32 GB of disk, UEFI 2.3.1c firmware with Secure Boot, and TPM 2.0 for some features such as BitLocker and Credential Guard. Server 2022 has the same list without the SSE4.2 and POPCNT requirement. Server 2019 and 2016 run on older hardware without TPM or Secure Boot.

In a virtual machine, allocate at least 2 vCPUs and 4 GB of RAM for Desktop Experience, use a Generation 2 VM on Hyper-V (or UEFI firmware in VMware and Proxmox) for 2022 and 2025, and attach the ISO to the virtual DVD drive rather than making a USB stick.

Step 1: download the correct ISO

Use the Microsoft link in your delivery email. It takes you to Microsoft’s download page for the version you bought, in your language. Microsoft publishes the evaluation ISO publicly; the installed product is identical to the full edition, and a retail key either activates it directly (2016 and 2019 full media) or after a one-command conversion (evaluation media, covered below). Do not download Windows Server from third-party mirrors; the hash of the official ISO is published by Microsoft and a modified ISO can refuse retail activation.

Step 2: create bootable media

For a physical server, download Rufus, insert an 8 GB or larger USB drive, select the ISO, choose GPT partition scheme and UEFI target, and click Start. Rufus handles the install.wim size limit automatically by splitting it. Our general bootable USB guide covers the tool in detail. For a virtual machine, attach the ISO to the VM and set the boot order to DVD first.

Step 3: choose the edition and installation option

Boot the media and follow the prompts. Two choices during setup decide whether your key will activate.

Edition. The list shows Standard and Datacenter, each twice. Pick the edition on your order. A Windows Server 2025 Standard key activates Standard only; a Windows Server 2025 Datacenter key activates Datacenter only. If the wrong edition is installed, you cannot move Datacenter down to Standard; Standard can be moved up to Datacenter with DISM.

Installation option. “Desktop Experience” installs the full graphical interface; the entry without it installs Server Core, which is managed through PowerShell, Windows Admin Center or a remote Server Manager. Core is lighter and more secure, Desktop Experience is easier for a single server. Both use the same key; the choice cannot be changed after installation without reinstalling.

When setup asks for a product key, you can enter it now or click “I don’t have a product key” and enter it after installation. Entering it later is often more reliable because the activation then runs with full network drivers loaded.

Step 4: finish setup and apply updates

Set the administrator password, sign in, and let the server pull drivers and updates. Run Windows Update until no further updates are offered; on 2025 the first cumulative update is large. Set the time zone and a hostname before activation, because a change to the computer name after activation can occasionally trigger a re-activation prompt in domain environments.

Step 5: activate

Full media (2016 and 2019 retail ISO, or any converted evaluation): open Settings, System, Activation (Desktop Experience) and click Change product key, or run from an elevated prompt:

slmgr /ipk XXXXX-XXXXX-XXXXX-XXXXX-XXXXX

slmgr /ato

Confirm with slmgr /xpr, which should report “The machine is permanently activated”.

Evaluation media (the common case for 2022 and 2025): run DISM /Online /Get-CurrentEdition. If the edition ends in “Eval”, convert with:

DISM /Online /Set-Edition:ServerStandard /ProductKey:XXXXX-XXXXX-XXXXX-XXXXX-XXXXX /AcceptEula

Use ServerDatacenter for Datacenter. The server restarts twice and comes back as a full edition, then activate with slmgr /ato. Our dedicated article on converting a Windows Server evaluation covers the error cases.

Server Core: the same slmgr commands work from the command prompt that opens at sign-in, or use sconfig option 11 (Windows activation) which wraps them in a menu.

Activation refused? The three usual reasons

1. Edition mismatch. winver shows Datacenter but the key is Standard, or vice versa. Reinstall or convert as described.
2. Key still counted against a previous installation. Common on rebuilt servers and lab machines. Run telephone activation with slui 4, or send the installation ID to our free Confirmation ID service.
3. Online activation refused with 0xC004C003 or 0xC004C008. Microsoft’s fraud checks declined the request. Telephone activation resolves it. See keys reported as used or blocked.

If telephone activation also refuses, send us a screenshot of the activation page and your order number; replacements and refunds are covered by the 180-day money-back guarantee.

Version notes and support dates

Version	Released	Mainstream support ends	Extended support ends	Notes
Windows Server 2025	1 Nov 2024	9 Oct 2029	10 Oct 2034	Hotpatching, SMB over QUIC, Active Directory improvements
Windows Server 2022	18 Aug 2021	13 Oct 2026	14 Oct 2031	Secured-core server, TLS 1.3 by default
Windows Server 2019	2 Oct 2018	9 Jan 2024	9 Jan 2029	Last version with Essentials as a separate SKU widely used
Windows Server 2016	12 Oct 2016	11 Jan 2022	12 Jan 2027	Still common on older hardware

Mainstream support for Server 2022 ended on 13 October 2026, so new deployments should use 2025 unless an application vendor has not certified it yet. Windows Server 2022, 2019 and 2016 licences remain available for existing environments.

After activation: licensing the clients

The server licence covers the operating system on the server. Users and devices that connect to it need Client Access Licences, and Remote Desktop Session Host needs RDS CALs, which are enforced after a 120-day grace period. Plan CALs when you plan the server; they are not something setup asks about and the server will not warn you, except for RDS.

Checklist

1. Confirm hardware or VM meets the requirements (UEFI, Secure Boot and TPM 2.0 for 2022 and 2025).
2. Download the ISO from the official link in your delivery email.
3. Write it to USB with Rufus or attach it to the VM.
4. Choose the edition on your order and the installation option you can manage.
5. Finish setup, update Windows, set hostname and time zone.
6. Convert evaluation media with DISM if the edition ends in “Eval”.
7. Activate with slmgr /ipk and slmgr /ato; confirm with slmgr /xpr.
8. Use telephone activation if the online request is refused.

Installing on a physical server: firmware settings that matter

Before booting the USB drive on a physical server, open the firmware setup and check four settings. Set the boot mode to UEFI rather than Legacy or CSM, because Windows Server 2022 and 2025 require UEFI and the GPT partition scheme that Rufus writes. Enable Secure Boot; setup for 2025 will not proceed on an unsupported configuration. Enable the TPM (often called PTT on Intel boards and fTPM on AMD boards) so that BitLocker and virtualisation-based security are available later. Finally, set the SATA or NVMe controller to AHCI or RAID mode as appropriate and have the vendor’s storage driver on a second USB stick if the disk does not appear in setup; Dell PERC, HPE Smart Array and Lenovo RAID controllers frequently need their driver loaded with the “Load driver” button on the disk selection screen.

Post-installation tasks worth doing before the server goes live

Rename the computer and restart. Set a static IP address or a DHCP reservation. Join the domain if there is one. Enable Remote Desktop for administration (System Properties, Remote) and, on Server Core, enable it with sconfig option 7. Install the roles the server was bought for through Server Manager or Install-WindowsFeature. Turn on Windows Defender’s real-time protection if the application vendor does not object, and schedule a weekly backup with Windows Server Backup or your backup product. None of these steps affects activation, but doing them in this order avoids the re-activation prompts that a late hostname change can cause in a domain.

Choosing a licence first? Read the Windows Server product key buying guide for editions, cores, CALs and prices.

Frequently asked questions