How do you get gamer tag points on xbox 360?

I want to change my name but it says that i cant.How do you get gamer tag points on xbox 360?you get gamer tag points, by getting achievements from all of your 360 and arcade games.

and you need 800 Microsoft points to change your name. http://support.microsoft.com/kb/908658How do you get gamer tag points on xbox 360?No such thing as those points. To change your name or buy almost anything on Xbox Live, you need Microsoft Points, and these must be bought, either from a store in card form, or from Xbox Live itself using a credit card.How do you get gamer tag points on xbox 360?You can buy those points in stores/xbox live. They do cost money and they are not free.