Windows 10: Licence not linked to Microsoft Account

I got my Mum a new PC to replace her current one as it's been having some hardware issues. I changed her from a local account login to using her outlook.com account and that's fine but it doesn't seem to have linked her licence with her MS account, as when I login with her outlook.com account on the new PC it's not activated. Selecting "Troubleshoot" returns "We weren't able to activate Windows on this devices" and clicking "I recently changed hardware on this device" returns "We cant find any devices linked to your Microsoft account that can be used to reactivate the device that youre using at the moment. Make sure that youre signed in with the same Microsoft account that you linked to the Windows 10 digital licence on this device, or try again later. "

Her old PC was upgraded from Windows 8 to Windows 10 and it says "Windows is activated with a digital licence linked to your Microsoft Account". At https://account.microsoft.com it shows two devices, her old PC with Windows 10 Pro v1903 and her new one with Windows 10 Pro v1909 and neither say activated but maybe it's not meant to say that there?

So what do I need to do to get Windows on her new PC activated?

:)

 

How to verify that my Windows 10 licence is associated with my Hotmail/Microsoft account

Do those steps:

• Use the keyboard shortcut Windows-I to open the Settings application.
  
• Select Update & Security.
  
• Select Activation
  

Here you see the current status. If the account has no licence you can click on Add an account, enter your account data and the account gets the license added.

You can see this in the next step in the same dialog:

 

Licence not linked to Microsoft Account

I got my Mum a new PC to replace her current one as it's been having some hardware issues. I changed her from a local account login to using her outlook.com account and that's fine but it doesn't seem to have linked her licence with her MS account, as when I login with her outlook.com account on the new PC it's not activated. Selecting "Troubleshoot" returns "We weren't able to activate Windows on this devices" and clicking "I recently changed hardware on this device" returns "We can’t find any devices linked to your Microsoft account that can be used to reactivate the device that you’re using at the moment. Make sure that you’re signed in with the same Microsoft account that you linked to the Windows 10 digital licence on this device, or try again later. "

Her old PC was upgraded from Windows 8 to Windows 10 and it says "Windows is activated with a digital licence linked to your Microsoft Account". At https://account.microsoft.com it shows two devices, her old PC with Windows 10 Pro v1903 and her new one with Windows 10 Pro v1909 and neither say activated but maybe it's not meant to say that there?

So what do I need to do to get Windows on her new PC activated?

 

Licence not linked to Microsoft Account

The new PC is secondhand with a clean install of Windows 10 but as her Windows 10 licence is linked to her MS Account I understood that this allowed her to reactivate if she changed hardware. I'm logged in on the new PC with her MS Account rather than a local account.