My girlfriend recently bought a brand new laptop, straight off the shelf, and we installed Fallout 3 on it, as I play it regularly on my rig. It runs fine with zero problems on mine, but not on hers. The primary problem with it on her laptop is a game-busting freeze that occurs 5 minutes into the game, every single time. Only once have we gone 30 minutes in with no issues, but had to shut the game down (it was late). But so far, I have scoured the internet for answers and have tried most of everything. Patching doesn't work, updating the system doesn't work, changing small things doesn't work. It all still crashes. The system is:

Intel Core i3 CPU 2.53Ghz
4GB RAM
ATI Radeon HD5470

And yeah. In game, the graphics are perfect on all settings with no lag whatsoever, so we're well within the system requirements. I think it's only one core, not Duo or Quad core, and the graphics drivers are up to date. So, anyone know mostly HOW to fix this issue?
Cheers!

Sounds almost exactly what I got, computer and problem, except my Intel Core i3 is 2.27Ghz.

It's a real pain in the crack, hopefully someone gives us a hand!

So I guess I should just give up then?

I just found this bit about changing "bUseThreadedAI=0", replacing the 0 with a 1. Then you press enter and insert "iNumHWThreads=2". So far the only trouble I've found is when I quicksave!

Where exactly does it lock-up?

Have you noticed if music is playing on the Main Menu (on either machine)? This seems to be a clue about a problem that might be present.

It should work fine on that hardware. Check out http://www.gamesas.com/index.php?/topic/1187018-fallout-3-goty-controls-and-game-freeze/