Microsoft Windows Server 2025 — 1 Device CAL: Installation, Licensing, and Configuration

Before You Begin

Microsoft Windows Server 2025 is the latest version of Microsoft's server operating system, designed with modern IT environments, security, and performance in mind. This version introduces a range of improvements in management, container handling, security, and cloud integration.

Windows Server 2025 licensing is based on two main elements: server license and client access licenses (CAL — Client Access License). Each device or user accessing server services must have the appropriate CAL license. In this article, we focus on Device CAL — a license assigned to a device, allowing any number of users to access server services from that specific device.

What Does KluczeSoft Provide?

• Original Device CAL license key — for use on one device.
• VAT invoice and purchase certificate — necessary for audits and proof of legality.
• Technical support — assistance with implementation and troubleshooting.
• Step-by-step instructions — on how to implement and manage the Device CAL license.

Support Terms

Note: Device CAL does not include the server operating system. You must have a separate license for Windows Server 2025.

System Requirements

Before purchasing and deploying Device CAL, ensure your server meets the minimum system requirements for Windows Server 2025. Below is a detailed table consistent with Microsoft documentation:

Tip: In production environments, higher hardware parameters are recommended, especially with many users and services.

Step 1: Installing Windows Server 2025 — Step by Step

Below, you will find a detailed instruction for installing Windows Server 2025. We assume that you already have an installation media or ISO image and a valid server license.

1.1. Preparing the Installation Media

• Download the official Windows Server 2025 ISO image from the Microsoft portal or use the media provided by KluczeSoft.
• Create a bootable USB drive (e.g., using the Rufus tool) or burn the image to a DVD.

1.2. Running the Installer

• Connect the media to the server and start the computer.
• In the BIOS/UEFI, set the boot device to USB/DVD.
• After starting, you will see the "Windows Setup" screen.

1.3. Selecting Language and Regional Settings

• On the "Windows Setup" screen, select:
  • Installation language: Polski
  • Time and currency format: Polski (Polska)
  • Keyboard: Polski (programisty)
• Click Dalej.

1.4. Starting the Installation

• Click Zainstaluj teraz.

1.5. Entering the Product Key

• Enter the Windows Server 2025 product key (not Device CAL!).
• Click Dalej.

1.6. Selecting the System Edition

• Choose the appropriate edition (e.g., Standard, Datacenter).
• Check the box "Akceptuję warunki licencyjne".
• Click Dalej.

1.7. Selecting the Installation Type

• Nowa instalacja (Custom: Install Windows only)
• Specify the target partition or create a new partition.
• Click Dalej.

1.8. Installation and Account Configuration

• The installer will copy files and restart the computer.
• After restarting, set a password for the Administrator account.
• Log in to the system.

Tip: After installation, we recommend installing the latest system updates immediately.

Step 2: Installing and Managing Device CAL

2.1. What is Device CAL?

Device CAL (Client Access License) is a license assigned to a specific device that accesses Windows Server 2025 services. Example: a computer at the reception desk used by several employees — only one Device CAL is required.

2.2. How to Assign Device CAL?

• Device CAL does not require technical activation on the server.
• After purchase, you receive a certificate or invoice, which you should keep as proof of legality.
• In case of a Microsoft audit, you may be asked to present the purchase documentation.

2.3. Documentation and Compliance

• Keep the invoice, certificate, and any email confirmations.
• We recommend keeping a record of devices assigned to Device CAL (e.g., in Excel or an ITSM system).

Note: Assigning Device CAL is an administrative decision, not a technical one — no key is entered into the system.

If you have any questions or need further assistance, please contact us at [email protected] or call 00 800 121 1654.

Step 3: Activation with a Product Key (for Windows Server)

Although Device CAL does not require activation, the Windows Server 2025 system itself must be activated. Below, you will find two activation methods: via the graphical interface and the command line.

3.1. Activation via the Graphical Interface

1. Open Settings > System > Info.
2. Click Activation.
3. Enter the Windows Server 2025 product key.
4. Click Next and follow the instructions.

3.2. Activation via the Command Line

1. Open the Command Prompt as an administrator.
2. Enter the command:

C:\Windows\System32\slmgr.vbs /ipk XXXXX-XXXXX-XXXXX-XXXXX-XXXXX

1. Then activate the system:

C:\Windows\System32\slmgr.vbs /ato

Tip: If errors occur, check your internet connection or try phone activation.

3.3. Verification of Activation

To check the activation status, use the command:

C:\Windows\System32\slmgr.vbs /xpr

A window will appear with information about the activation status.

Step 4: Verification of Device CAL Assignment

Since Device CAL is not technically activated, verification involves checking documentation:

• Check if each device accessing the server has an assigned Device CAL.
• In the event of an audit, present the invoice and device records.

Example: If you have 10 computers in the office using the server, you must have 10 Device CALs.

Step 5: Post-Installation Configuration

After installing and activating the system and assigning Device CAL, perform basic configuration tasks:

5.1. Installation of Updates

• Open Windows Update and install all available fixes.

5.2. Configuration of Roles and Features

• Open Server Manager.
• Click Add Roles and Features.
• Select the required roles (e.g., Active Directory, file server, DNS).

5.3. Creation of Users and Groups

• Open Active Directory Users and Computers.
• Add users and assign them the appropriate permissions.

5.4. Network Configuration

• Configure IP addresses, DNS, default gateways.

5.5. Backup and Security

• Configure the backup schedule.
• Enable the system firewall and configure security policies.

If you need help or have questions, please contact us at [email protected] or call 00 800 121 1654.

Step 6: Troubleshooting

Below, you will find the most common issues related to licensing and access to Windows Server 2025, along with their solutions.

6.1. Error: "No CAL license for this device"

• Description: The user cannot access server services.
• Solution: Check if the device has an assigned Device CAL. Update the records, purchase missing licenses.

6.2. Activation error: 0xC004F074

• Description: Problem with communication with the activation server.
• Solution: Check the network connection, try phone or internet activation again.

6.3. Error: "Cannot add role due to lack of permissions"

• Description: Lack of administrator permissions.
• Solution: Log in to the Administrator account or grant the necessary permissions.

6.4. Error: "Remote Desktop Services requires additional CAL"

• Description: Attempt to use remote desktop services without the appropriate RDS CAL.
• Solution: Purchase and assign the appropriate RDS Device CAL.

6.5. Error: "Invalid product key"

• Description: The product key was entered incorrectly.
• Solution: Check the correctness of the key, enter it again, make sure you are using the key for Windows Server 2025, not Device CAL.

6.6. Problem: "CAL compatibility issue with server version"

• Description: An older version of CAL was assigned to a new server.
• Solution: Use Device CAL for Windows Server 2025, which are backwards compatible, but not the other way around.

Step 7: Comparing versions and prices at KluczeSoft

The following table presents a comparison of Device CAL for different Windows Server versions and their prices at KluczeSoft:

Tip: Windows Server 2025 Device CAL are compatible with earlier server versions, which simplifies license management in mixed environments.

More information and purchase: /windows-server-2025

Summary

Purchasing and deploying Microsoft Windows Server 2025 1 Device CAL is a process that requires understanding the licensing model and proper documentation. Device CAL is a convenient solution when multiple users use a single device. Remember that:

• Device CAL is assigned administratively, not technically.
• Each device using the server must have its own Device CAL.
• Purchase documentation is crucial during audits.
• For remote services (RDS), additional CAL are required.

If you have any questions or problems, please contact our technical support department:

Phone: 00 800 121 1654

You can find more information on the product page: /windows-server-2025

For further assistance, you can also contact us at [email protected]