When I reviewed my profile on the website, it has a list of Halo games with my service record for each – which is pretty cool!
However, it is missing one major element, which is that it says I have never played Halo 2, while I have in fact gotten about a third of the way through Halo 2 on PC (before Halo 4 came out and my attention was pulled away from Halo 2 until I acquired the Master Chief Collection for XBox 1.)
After I created my XBox Live (Gold) / Games For Windows Live account, I have never changed my Gamertag, so that is not the issue in this case.