How do you restore a deleted XBOX ONE account?

You may want to take a look at this site:

manage gamertag and profile

If you can login to the account from a PC or tablet on Microsoft and see what it says there. If you are a parent account login to your account and see if there are any messages related to your sons account.

soif there is no account on the xbox itself when you choose sign in it will ask you to add an account. you should hae this option even wit accounts on the system.

it will ask ou tolog in with the email and password associated with the account and will automatically downloa your profile to the onsole. all gamebought digitally and any saved dat will still remain available once you have added the account back to the
system

That worked! He thanks you so much!

Thank you I'll try that

Hi Chad,

Thank you for coming to the Xbox forums, I'd be happy to help.

You can
add your Microsoft account to any Xbox One console. Here's how:

1. Press the Xbox button to open the guide.
2. Select your gamerpic in the upper-left corner of the screen, move all the way down and select
   Add new.
3. Enter the email address for the Microsoft account that you want to add, and then select
   Enter.
   
   Important Make sure that you do not select
   Get a new account, unless that’s what you want to do. If you select this, you will create a brand-new Microsoft account.
   
   If you’ve forgotten which email address is associated with your Microsoft account, see the
   
   Lost Account Solution.
4. Enter the password for your Microsoft account that you want to add, and then select
   Enter.
5. Read the Microsoft Service Agreement and Privacy Statement, and then select
   I Accept.
6. Follow the steps to configure your Sign-In & Security preferences to add your Microsoft account to your Xbox One console.

Everything will be restored once the account is added back.

I hope this helps!