Changing gamertag without using an Xbox360/One console

I installed it from a different source, but now I try to reinstall it from the link you provided. MS points have been indeed discontinued, or at least was offered me to buy x amount of MS points for X amount of currency.

Edit: I reinstalled the client from the link you provided, but it still gives me an error message, nonetheless, a different one alltogether.

 

It turns out that with the new Marketplace client, I wasn't able to start any of the games that still use Windows Live in my Steam catalog (Dirt3, F1 2011). I had to uninstall it, reinstall the one that was provided in the Dirt 3 install folder, which gave
me the original error message, but allow me to launch the game. I usually make a point out of buying the games I really love but things like this just make me second guess my decision...

 

When in game are you pressing the Home key on your keyboard? That is the one that brings up the in-game client where you change your gamertag. If you already had GFWL titles installed then you didn't need to download anything.

Anyway it is all academic since you can't redeem any codes or purchase points. So it turns out it was I that needed to do some fact checking as well.

 

Yeah, I did press the HOME key and it did bring up the in-game client. Nonetheless, it gives me the error message I mentioned earlier, so it doesn't allow me to change anything. I understand that they want people to buy the consoles, but the gamertag is
also used on Windows 8 PCs and Windows Phone 8 devices, so there's no logic in not allowing to change your handler from any of those devices.

Still, thank you for your suggestions, I really appreciate you taking the time to answer me.

 

No worries and I can only apologise for bring a measure of false hope.