How to Install and Activate Windows Server 2025

Activate Windows Server 2025 Standard or Datacenter after checking the installed edition, converting Evaluation builds when necessary, and completing online or telephone activation.

Before you begin: check that Windows Server 2025 is not installed as an Evaluation edition, apply pending server updates, confirm whether the license is for Standard or Datacenter, and have the valid product key available.

1. Validate the Windows Server 2025 edition

A Standard or Datacenter retail key cannot be applied directly to an Evaluation installation. Open PowerShell or Command Prompt as administrator and inspect the current and supported target editions:

DISM /Online /Get-CurrentEdition
DISM /Online /Get-TargetEditions

If the current edition includes Eval or Evaluation, convert it before proceeding. Replace XXXXX-XXXXX-XXXXX-XXXXX-XXXXX with the key that belongs to the target edition.

Convert to Windows Server 2025 Standard

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

Convert to Windows Server 2025 Datacenter

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

Only select a destination returned by Get-TargetEditions. Restart after DISM completes and verify the result again with DISM /Online /Get-CurrentEdition.

2. Find the Server 2025 activation controls

From the Start menu, open Settings. Go to System > Activation to review the server edition and its current licensing state.

System Activation page in Windows Server 2025 — The modern Activation page displays the installed Server 2025 edition and status.

3. Install the Windows Server product key

Open Change product key, select Change, and approve the administrator prompt if one appears.

Change product key option in Windows Server 2025 — Open the product-key dialog from Server 2025 activation settings.

Enter all 25 characters, select Next, and let the server validate the license. A converted edition may require another restart before the final status is available.

Product key entry window for Windows Server — Supply the product key for the installed Standard or Datacenter edition.

4. Determine whether telephone activation is required

A successful activation state completes the procedure. You can also run slmgr /xpr in an elevated terminal for a quick license check.

If error 0xC004C008 prevents online activation, dismiss the error and continue below to generate an Installation ID.

Windows Server activation error 0xC004C008 — Use the telephone procedure when online activation returns 0xC004C008.

Windows Server 2025 activation error details — Close the error details before moving to the manual method.

5. Open the telephone activation wizard

Choose Activate by phone from the available options. If no link is shown, press Windows + R, type slui 4, and select OK.

Activate by phone option in Windows Server 2025 — Start the telephone wizard to obtain the Server 2025 Installation ID.

6. Capture the Installation ID

Select a country or region and continue. The location only advances the wizard; it does not alter the server language or regional configuration.

Copy the complete Installation ID (IID), preserving the sequence of every displayed group.

Installation ID shown by Windows Server telephone activation — Record every IID group before leaving the activation wizard.

7. Exchange the IID for a Confirmation ID

Select the method you prefer for obtaining a Confirmation ID (CID):

Microsoft Product Activation Portal: the official free choice. It requires a Microsoft sign-in and manual entry of the Installation ID.
InstantLicX Telegram bot: a faster paid route. Send the IID as text or a screenshot directly to the Telegram bot.
GetCID.xyz: a paid browser-based service with text and image recognition, plus an API, WordPress plugin, and WhatsApp and Telegram bots.

Use Microsoft’s free portal manually

Open the Microsoft Product Activation Portal, authenticate with a Microsoft account, and select Activate a Microsoft Product.

Select Windows, choose Windows Server 2025 when available or the closest server entry offered, and proceed to the Installation ID form.

Microsoft product activation selection — Choose to activate a Microsoft product.

Windows product list in Microsoft Activation Portal — Select Windows and the best matching server version.

Submit the complete IID after checking that none of its groups are missing or out of order.

Microsoft Installation ID submission form — Enter the entire Server 2025 Installation ID.

For a new activation, answer 0 if the portal asks how many computers have used this copy.

Microsoft activation computer count question — Use 0 for a new activation when prompted for a device count.

8. Enter the Server 2025 Confirmation ID

The chosen service returns a Confirmation ID after accepting the IID. Copy each group in the order displayed.

Confirmation ID produced after IID validation — Copy the generated Confirmation ID without changing the group order.

Return to the telephone activation window, enter every CID group in its matching box, and select Activate Windows.

Windows Server Confirmation ID fields — Place each CID group into the corresponding activation field.

9. Confirm the Windows Server 2025 license

Reopen Settings > System > Activation and confirm the active state. For command-line verification, run slmgr /xpr as administrator.

Windows Server 2025 activation status showing active — Verify that Server 2025 now reports a successful activation.

Troubleshooting Server 2025 licensing

Run DISM /Online /Get-CurrentEdition and confirm that the edition no longer ends in Eval.
Verify that the key type and edition match Windows Server 2025 Standard or Datacenter as installed.
Complete pending servicing operations and restart the server before another attempt.
Use slmgr /dlv when detailed licensing data or the current error code is needed.
Recheck the position of all IID and CID groups before requesting a replacement Confirmation ID.