If you don't recognize the gamertag, this may have been set up automatically if you haven't used Xbox's services on this specific Microsoft account before. However, you can always contact us at msft.it/6014ZtWVr if you're concerned, and we can investigate further. ^NS
Hello again! Yes, we understand you don't own an Xbox but you have migrated to a Microsoft account in which will set up a Microsoft Account for you. You can change your Gamertag/Username from your Microsoft Account if you needed ^TK

Jan 18, 2022 · 12:13 AM UTC