Win11 activation after installing a new CPU and after BIOS Update

Question

Win11 activation after installing a new CPU and after BIOS Update

Thomas 0

Hi, I just noticed that Win11 is no longer activated, after changing my CPU, additionally I made a BIOS Update first. My licence of that PC was connected to my account, but is no longer. Do I need to change the CPU back? Thanks in advance for any help.

EmilyS726 271.5K Reputation points Independent Advisor

2026-09-02T20:02:37.79+00:00

Hello,

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?

1 answer

Your answer

EmilyS726 271.5K Reputation points Independent Advisor

2026-09-02T20:02:37.79+00:00

Hello,

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?

Answer 1

A CPU change or BIOS update can be treated as a significant hardware change, so Windows 11 may stop activating. Changing the CPU back is not the documented first step.

Try this in order:

Check activation status:
- Start > Settings > System > Activation
- Confirm whether it shows Windows is not activated and note any error.
Run the Activation troubleshooter:
- Start > Settings > System > Troubleshoot
- This option is available only when Windows is not activated.
- An internet connection is required.
- Administrative sign-in is required.
If the device had a digital license linked to the Microsoft account before the hardware change, use the reactivation path for recent hardware changes from the troubleshooter.
If a product key is available, enter it here:
- Start > Settings > System > Activation > Change product key
- Enter the 25-character key and follow the prompts.
Verify that the installed edition matches the license:
- In Settings > System > Activation, check whether the device is running the same edition the license is for, such as Windows 11 Home or Windows 11 Pro.
- If the edition does not match, Windows will not activate.
If the troubleshooter does not reactivate Windows after the CPU/BIOS change, contact Microsoft customer support.

If the motherboard was replaced by the original hardware manufacturer, the PC should reactivate automatically. If not, and a COA key was provided by the OEM, that key can be entered through Change product key.