I don’t want to use the current gamertags and would like to change it to a particular one which I search for on xboxgamertags.com without any kind of results showed up. However, when I tried to apply it and check availability, it said that it was unavailable yet. I called Xbox support and could not get help with this. It seem that such Gamertag was retired likely.
A few people have faced the same problem that changing their gamertag receives the it was unavailable error. There is nothing to deal with that one and you have to just choose another one to use.
* If there is any spaces within the GT, that might cause the problem. The system doesn’t find the things like spaces or the related information. For example, the xboxgamertags.com site doesn’t display the “Ma Neson” from results, but looking for “Ma Neson” and this is the actual gamertag and still in use.
* In the addiction, the gamertag is unavailable for some other reasons, because it contains banned words, tied to another Microsoft account through Zune, or other unknown reasons and then it is unavailable. So the only way is to choose another.
Many people have noticed that a lot of the best and most desirable Gamertags were unavailable and they have to immediately get the Name for another GT. If you are valued Xbox Live Gold customers with active subscriptions and at least one year of cumulative Xbox Live Gold tenure, now Team Xbox release a large number of previously-unavailable Gamertags that is nearly One Million and you are able to have an equal chance to get one. This is a good news.