Can I reinstall Windows 11 after replacing it with Ubuntu if I no longer have the product key?

Question

Hello,

I have an HP 15s i5 laptop currently running Windows 11. I am planning to completely remove Windows and install Ubuntu for a temporary testing project.

My main concern is what happens afterward if I want to return to Windows 11.

I do not have a product key available, so I would like to confirm the following:

If I erase Windows 11 and install Ubuntu, can I later reinstall Windows 11 on the same laptop without entering a product key?

Is the Windows license stored digitally on the device or linked to the motherboard/hardware?

After reinstalling Windows 11, will activation happen automatically once I connect to the internet?

How can I verify in advance whether my current Windows 11 license is a digital license?

Is there anything I should check before deleting Windows, in order to avoid activation problems later?

For context, I am not changing the motherboard or major hardware. I only want to temporarily use Ubuntu, then possibly reinstall Windows 11 on the same device later.

I would appreciate any guidance.

Thank you.

Answer 1

1

If Windows was pre-installed by HP on that device, then there is an OEM licence stored on the motherboard and any time you re-install or reset Windows, it will activate automatically from that OEM licence.

I can check that for you to ensure you will not experience any activation problems when you re-install Windows.

Click your Start Button, type cmd then right click Command Prompt and choose 'Run as Administrator'

Run or paste this command and hit Enter:

slmgr.vbs /dlv

Please post a screenshot of the resulting dialog

2

Also, when you install Linux on that device, that will change the format of the drive and you may need to disable Secure Boot in BIOS, so when you go to re-install Windows later, you will need to delete all partitions form the drive and re-enable Secure Boot.

Answer 2

Yes, Windows 11 can be reinstalled later on the same laptop without entering a product key, as long as it is currently activated and has a digital license for that device.

Addressing each point:

1. Reinstalling Windows 11 after Ubuntu without a product key
   If the device already has an activated Windows 11 with a digital license, the same edition of Windows 11 can be reinstalled on that device without entering a product key. During setup, when asked for a key, select "I don't have a product key". Windows 11 will automatically activate online after installation completes, provided it is the same edition and on the same device.
2. Where the license is stored (digital license / hardware)
   Windows 11 commonly uses a digital license that is associated with the device and, when linked, with a Microsoft account. Once the license is registered for that hardware, reinstalling the same edition on the same device does not require re-entering a product key.
3. Automatic activation after reinstall
   After reinstalling Windows 11 on the same device and connecting to the internet, activation should occur automatically if:

• The same edition of Windows 11 is installed, and
• The device already had an activated digital license for that edition, and
• The hardware (especially the motherboard) has not been changed.

4. How to verify that the current license is a digital license
   Before removing Windows:

• Select Start → Settings → System → Activation.
• Check the activation status. Possible messages include:
  • "Windows is activated with a digital license"
  • "Windows is activated with a digital license linked to your Microsoft account"

If one of these appears, the device has a digital license. If it is linked to a Microsoft account, that will also be indicated.

5. What to check before deleting Windows to avoid activation problems
   Before installing Ubuntu and removing Windows:

• Confirm activation status: In Settings → System → Activation, verify that Windows 11 is activated.
• Link the digital license to a Microsoft account (recommended):
  • If the page shows "Windows is activated with a digital license" (not yet linked), follow the instructions there to link the license to a Microsoft account.
  • Once linked, the status should show "Windows is activated with a digital license linked to your Microsoft account".
• Ensure you know the exact edition of Windows 11 (e.g., Home, Pro) and reinstall the same edition later. When creating installation media from the Microsoft software download website, choose the edition that matches what is currently installed.

When you later reinstall Windows 11:

• Boot from the Windows 11 installation media.
• If prompted for a product key, select "I don't have a product key".
• Complete installation, connect to the internet, and sign in with the same Microsoft account (if the license is linked). Activation should then complete automatically.

If activation fails after reinstall, use Settings → System → Activation and, if needed, the activation troubleshooter or the guidance in Get help with Windows activation errors.

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References:

• Activate Windows
• Reinstall Windows with the installation media
• Find your Windows product key
• Reactivating Windows after a hardware change