wow so you really can't play steam games without signing in (though it can be offline, thanks for the info guys), I went into the actual steam folder where they keep all the fallout new vegas data and tried launching the independent launcher from there but it still launched steam as well. since it's offline though it's not that bad and holy fuck I can't believe how stupid I was last time I played new vegas; I basically just worked on the main quest and immediate sidequests and now since you can't play after you beat it I've restarted to make a good character for the DLC and I've already been to 5 new places I never even saw, found 3 new enemies I never knew existed, new gear, tons of fun new quests etc. I really need to make sure that from now on despite the temptation that I play as many side quests and explore as much as I can in any game like this, even if it means taking a while to beat the main quest (I've done about 5%, up to Novac where they want you to go to repconn which I hated and now I'm just exploring and doing other shit).