iv been playing fallout 3 for the past 2 weeks now and have had no problem with it. Then i bought dirt 3 and in order to play i had to make a windows live account or something like that... so i made one and when i went to play dirt 3, windows live asked for the activation key and i entered it and it was all good, i did this for all my games and no problems. Then i went to play fallout 3 and it asked for an activation key and i can't find one in the little booklet that comes in the case and there was no piece of paper that came with it either, i can still play the game by pressing cancel when it asks for the activation key but its bloody slow and its starting to get annoying. So my question is how do i stop it from asking? Does fallout 3 even come with an activation key? Because i didn't have to enter one when i first installed it.
And yes its a legit copy of fallout 3 and not a pirate version
The LIVE activation key should be on a sticker in the case, where the disc sits. If you created a new LIVE profile for Dirt 3, Fallout will try to use that ID rather than the one you created when starting Fallout, you will have to log out with your Dirt 3 credentials and sign in with you Fallout credentials. It can be a real pain if you used different credentials. I don't think the LIVE access key is stored in the registry either, have not seen anything to suggest that it is.
LIVE on the PC was a good idea, but MS really f'd up the implementation. The one good thing is that if you have XBox Live, you can log in with those credentials and the achievements on the PC game add to your XBL total.
You should check out The Fallout 3 Nexus, there are many great mods for the game there, like new weapons, skins, missions and more. They have a lot for Bethesda games (made Oblivion 500+ hours).