Windows 10: Xbox username

I had a really old account that has a username I want to use but I do not remember what email I used I do have some emails in mind or the password any possible way to delete the account without logging in I can provide proof that it's my account.

:)

 

Xbox Live username

So I made an Xbox Live account, right from my new Xbox. But I forgot I had a Windows 10 Xbox account, and would like to use my Windows 10 username. I can still change my Xbox Live account username but it is taken by
the Windows 10 account. I know that I could of used the Windows 10 account but its too late now because I have purchased Xbox Live on the console. Any idea how I can change my Xbox username to the one I have on Windows 10. *Not by paying to change the username,
and its okay to delete the Windows 10 account if that meant the username would become available.*

Moved from: MSN / Accounts, login, and signup / Change my profile/personal info

 

Xbox 360 cracked

Even though the hack is very complex, and should not be done by you and me, but the crack will let you play back-ups of your Xbox 1 and Xbox 360 games, and will boot all normal xbox games, yes all, not just the onces on the compatibilty list. So we are one step closer.

Source: TheINQ

 

Xbox Live Account Username

So I made an Xbox Live account, right from my new Xbox. But I forgot I had a Windows 10 Xbox account, and would like to use my Windows 10 username. I can still change my Xbox Live account username but it is taken by the Windows 10 account. I know that
I could of used the Windows 10 account but its too late now because I have purchased Xbox Live on the console. Any idea how I can change my Xbox username to the one I have on Windows 10. *Not by paying to change the username, and its okay to delete the Windows
10 account if that meant the username would become available.*