Hi Darhyl,
Thanks for trying to answer.
"Based on your description, the hacker was able to remove the account's primary email address/security info and replace it with their own email address, which is why there's an option that you can create a new Microsoft account using the same primary email."
There is no option to create the account again using his existing email address (gmail). When I try to register his account again with Microsoft, it says his account already exists. Since the hacker changed his email address on the MS account, why won't it let me use my sons email (gmail) to create the account again. We have control of the gmail account.
"Since the security info has been replaced by the hacker, I'm afraid there is no other working method to recover the Microsoft account, and Microsoft Support cannot help either."
Yes, I understand this (insane) concept as being bureaucratic stupidity/laziness, but in this case I'm not trying to recover. I'm trying to recreate his account with the underlying email (gmail) address.
"Also, you mentioned that you received an error when attempting to create a new Microsoft account using the same primary email. This is because your son's email address must be a Microsoft domain email address."
As far as I'm aware you can create a microsoft account with any external domain.
"Any Microsoft domain email address, such as an Outlook, Hotmail, MSN, or Live address, that has been deleted or removed/replaced (by a hacker) can no longer be associated with any Microsoft account, as stated in this article, particularly under "Remove an alias": https://support.microsoft.com/Outlook/add-or-remove-an-email-alias-in-outlook-com"
This refers to account related to Outlook.com, my son is using gmail.