Hi, I am an Independent Advisor.
Let me help you with this issue.
I understand you want to register your new laptop with your Microsoft Account.
As soon as you sign in to your computer using your Microsoft account, it will automatically register it under devices. https://account.microsoft.com/devices?refd=acco...
Are you using a Microsoft account to log in to your new computer?
If you are not using a Microsoft account to log in to your computer, please follow the steps below.
Go to Settings (press Windows + I)
Navigate to Accounts > Your Info
If it says “Sign in with a Microsoft account instead,” click that
Sign in with your Microsoft account email and password