Alright so.. it seems that loads of people have the same problem.
Problem is, I can't download Halo 3. I've never had that problem before, still play Assassins Creed II too, although when the game I want the most comes free, there's a river of problems flooding everything.
When I try to download the game, an error pop ups saying '' This item can't be downloaded from your locale. '' or whatever. My account was set to New Zealand at first, so I changed it, to Ireland, where I currently live, but the problem persisted. Then I've read a thread that suggested to reset your router, so I did that. Problem was still there.
Is there anything else I can do, or am I in a dead end here?