Hi my son is trying to sign into his Xbox account and when he writes his password, it then ...

Your sons friend can download his profile to your console provided he knows his email address and password.

To do that press the guide button, Press X to sign out then select 'Download Profile'

He can then be signed into his own account on one controller and your son can be signed into his account on the other controller.

Well what happened was that my son was getting frequent request to enter his password in. He followed the following instructions and this led him to close his current profile with all of the accumulated data. He is very upset and would like to recover all
of this data. Plus this did not solve the problem even with the new profile account he is still being prompted to put in his password on and on and on. We suspect that the issue is that when he first created his XBOX profile account we were with another internet
provider so our email address has changed. I made the changes to my Microsoft account however it dosent seem to synchronise with the XBOX ONE account profile. So how do we recover that lost profile and resolve the email and password issues.

You’re repeatedly prompted for your password when signing in on Xbox One

When trying to sign in to your Xbox One console, you’re repeatedly prompted to enter your password, and you can't complete sign-in.

Solutions

My son can sign in to his account fine. When he is playing Fifa 16 and he wants to access xbox live it says the parent needs to accept the new terms. When I put in my email and password it says it is wrong. When I try to sign in to my profile it says error
8015D003 but all details I am entering are correct.

All he can do is follow the instructions to reset his password -
support.xbox.com/.../forgot-microsoft-account-password

No one here can give him the password. Also, it is not a good idea to post personal information, such as an email address on public forums.

[quote user="Soultakerr"]he can come downstairs log onto one, but if he tries to log on to his 360 it says he needs a live account???[/quote]

On the One, with your son signed in, can he go to the left to open the slide-in guide, then to the cogwheel symbol and under account check what Microsoft Account email he is using?

Make note if it's the same email he is trying to use on the 360.

Additionally, have him sign in with the email at the
page for account security.

Check if his account is protected by Two Step Verification. If his account IS IN FACT PROTECTED by Two Step Verification, your son needs to create a so called "App Password" further down on that page, as the Xbox 360 can't (yet) work with the code request
for Two Step Verification.

After your son created an App Password, use THAT password instead of his "regular" password.