To activate Windows 11 Pro, you can follow these steps:

1. Ensure you have a valid product key: Make sure that the product key you purchased is for Windows 11 Pro.
2. Open Activation Settings: Go to Settings > Update & Security > Activation.
3. Enter your product key: If you see an option to enter a product key, click on it and input your Windows 11 Pro key.
4. Use Command Prompt (if necessary): If activation fails through the settings, you can try using the Command Prompt. Open Command Prompt as an administrator and enter the command: slmgr /ipk to install the product key, followed by slmgr /ato to activate it.
5. Check for errors: If activation fails, take note of any error codes that appear. You can look these up for specific troubleshooting steps.

If you continue to experience issues, ensure that your device is connected to the internet and that there are no restrictions preventing activation. Additionally, you may need to contact Microsoft support for further assistance if the problem persists.

References:

• Activate Windows
• Can't Activate Windows after MSFT Forced Upgrade to 11

To activate Windows 11 Pro on a PC where it is already installed, a valid license is required, either as a digital license or a product key.

1. Check current activation status:
   • Select Start > Settings > System > Activation.
   • Under Windows, check whether Windows is activated.
2. If there is no license yet (not activated):
   • A Windows 11 Pro license can be obtained in one of these ways:
     • Buy a new device that includes Windows 11 Pro (product key is provided with the device or embedded).
     • Buy Windows 11 Pro (full license or upgrade) from the Microsoft Store app (digital license linked to a Microsoft account).
     • Buy a box copy or digital copy of Windows 11 Pro from an authorized retailer (product key is in the box or confirmation email).
   • If there is no key or license yet and Windows 11 Pro is already installed:
     1. Go to Start > Settings > System > Activation.
     2. Select Go to Store (or Open Store) to open the Microsoft Store app.
     3. Purchase a Windows 11 Pro digital license. Once the purchase completes and the PC is online and signed in with the same Microsoft account, activation should occur automatically.
3. If there is a product key for Windows 11 Pro:
   • Select Start > Settings > System > Activation.
   • Choose Change product key.
   • Enter the 25-character Windows 11 Pro product key from the device packaging, Certificate of Authenticity, card, or confirmation email.
   • Complete activation while connected to the internet.
4. If online activation fails:
   • Use the activation troubleshooter from Settings > System > Activation as described in Activate Windows.
   • If still not successful, activation can be done by phone using the Activate by Phone option in Settings > System > Activation, or via the Product Activation Portal using the information shown on that screen.

References:

• Activate Windows
• Product activation for Windows - online & Microsoft Support Product Activation Portal

Try this activation path in Windows 11 Pro:

1. Check activation status: Start > Settings > System > Activation.
2. If Troubleshoot is available, run it. The troubleshooter is available only when Windows isn’t activated, and an administrator account is required.
3. Make sure the PC is connected to the internet, because Windows activation requires an internet connection.
4. If there is a Change product key option and a valid 25-character Windows 11 Pro key is available, enter it there.
5. If Windows 11 Pro was purchased digitally and activation still fails, run the troubleshooter again from Start > Settings > System > Activation > Troubleshoot.

If an error code appears, use the matching fix:

• 0x803F7001: No valid license was found. In Settings > System > Activation, select Change product key and enter the 25-character key. If there is no valid key, select Go to Microsoft Store to buy a digital license.
• 0xC004C003: The key entered isn’t valid for activation on that device. Run Troubleshoot from Settings > System > Activation. If the device is new or came with Windows preinstalled and failed on first startup, contact the device manufacturer. If the key came from a reseller, contact the reseller.
• 0xC004F034: The key is invalid or for a different Windows edition. Enter a valid key that matches the installed Windows 11 edition.
• 0x80004005: Run the Activation troubleshooter. If that does not work, a device reset might be required. Warning: resetting the device can remove apps and data depending on the reset option chosen.
• 0x87e10bc6: Wait a few minutes, then run Troubleshoot from Settings > System > Activation. When it finishes, select Go to Microsoft Store and then Try again.

If Windows 11 Home is installed but the license is for Windows 11 Pro, open the troubleshooter and select Upgrade to Windows 11 Pro.

If online activation fails, Windows 11 also supports activation by phone:

1. Go to Start > Settings > System > Activation.
2. Under Activate Windows Now, select Activate by Phone.

• Get help with Windows activation errors
• Using the Windows Activation troubleshooter
• Product activation for Windows - online & Microsoft Support Product Activation Portal

What's the context here?

First time using the license, or is this a reinstall?

How did you obtain your license initially?

Did it come with the device preinstalled, or did you purchase it?

If you purchased it, did you purchase from Microsoft, or from third party?

Is it originally a Win7/8 key?

Just to make sure, is motherboard changed?

Hi, Azalea David

Changing the Microsoft account or Windows PIN normally will not fix activation, because activation depends on a valid digital license or product key for that device and Windows edition.

Besides the solutions provided by the Q&A Assist, here are some suggestions you can try: 

Check whether the installed edition is Windows 11 Home or Pro. The license must match exactly. For example, a Home license cannot activate Windows 11 Pro. If the wrong edition was installed, you may need to reinstall the edition originally supplied with the computer.

Note the complete activation error code, such as 0x803F7001 or 0xC004C003. Each code indicates a different licensing problem, so the exact code is important.

If Windows came preinstalled and has never activated, contact the computer manufacturer. The license may be embedded in the device firmware, and the manufacturer should verify it.

If you bought the key separately, check the receipt or order history and contact the seller. A blocked, reused, or incorrect-edition key must be replaced with a valid one.

If the computer is refurbished, look for a Certificate of Authenticity label or card containing its Windows product key.

Please post the error code, Windows edition, and whether Windows came with the computer. Do not post the product key itself.

Thank you for your patience in reading, I hope this information has been helpful to you. 

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Hi Essau,

It doesn't change automatically.

You have to input the new Pro Key here: