I've looked on this forum and seen no posts like it, so I decided to make my own.

I recently received Halo 2 for Windows Vista for Christmas (purchased from Amazon) and installed it on my computer successfully. after loading up the game and passing the "any key to continue screen" I am given a windows LIVE prompt, telling me to log in to my account before i can play. I enter my LIVE account information and enter my activation code and it says its invalid, so I typed it in a couple more times to see if i was making any typos. after that i looked to Goggle and typed in my problem, turns out brand-new invalid keys for Halo 2 are pretty common, so much so that they've taken a toll off of the Halo 2 PC gaming community. Although, most of the answers led to old programs, support pages and out of date help that were completely useless. There was only one suggestion that was somewhat recent; calling Tech support, and even that ended up failing since Microsoft "no longer offers direct customer support for Halo 2" so I gave up and started playing Halo 1. I stumbled across this forum looking for Halo Mods and peeked into the Halo 2 section, and there are posts from this month, so I figured you guys have found some sort of miracle fix and that you could help me.

TL;DR: Activation code, brand new out of the package is invalid.

Best thing you can do is using a activation key from another game.

The only game that I know of from the top of my head that will allow you to use that key is Grand theft auto IV.