Old account comes back to life

Yes. The supported way is to switch the PC away from the old Microsoft account and then sign back in with the correct account.

If the old account password is still known:

1. Open Settings > Accounts > Your info.
2. Select Sign in with a local account instead.
3. Complete the prompts, then restart the PC.
4. Go back to Settings > Accounts > Your info.
5. Select Sign in with a Microsoft account instead.
6. Sign in with the current Microsoft account that should be associated with the laptop.
7. Restart again.

If Sign in with a local account instead is not shown, first select Stop signing into Microsoft apps automatically, then reopen Your info and try again.

If the old account password is not known, create a new Windows user and use the correct Microsoft account there:

1. Open Settings > Accounts > Other users and add a new account.
2. Sign in with the correct Microsoft account.
3. Sign out of the old profile and sign in to the new one.
4. If files exist under the old profile, copy them from C:\Users\<Old_Username> to C:\Users\<New_Username>.
5. After confirming the new account works and files are copied, remove the old Windows profile.

If the old identity is appearing because the Microsoft account itself still has outdated sign-in details, review the Manage how you sign in area and make sure any outdated alias is no longer primary. If a sign-in prompt appears asking Which account do you want to use?, that means a personal Microsoft account and a work or school account are using the same email address; those accounts cannot be merged.

If the old email address belonged to a closed Microsoft account, that address cannot be reused to create a new Microsoft account.

References:

• Change From a Local Account to a Microsoft Account in Windows | Microsoft Support
• Removal of previous Microsoft account information - Microsoft Q&A
• Which account do you want to use? | Microsoft Support
• How to create a new Microsoft account | Microsoft Support