Hi guys,
I wanted to pop in with some advice for those crashing on PC.

In your Fallout.ini file (\my documents\my games\Fallout3\)
Find the line:
bUseThreadedAI=0
Change it to:
bUseThreadedAI=1
Then add the line:
iNumHWThreads=2
And save your .ini file!

My game was unplayable until I did this (back in 2009).
I have recently had occasion to reinstall the game on my new x64 rig...
And was all in a panic because I had to rediscover this info!
(I have had to search back through this forum to February 3rd.)

Could somebody ie. CCNA please Sticky this info?
This info is not posted anywhere (apart from searching back into history) and I would describe it as VITAL!

Using this technique, plus running BOSS to sort load order, the vanilla game plus all five DLC (GOTY off Steam) is solid.
I did nothing at all regarding WindowsLIVE - don't know if that's applicable to Steam version?

Then I installed this guy Houck's epic quest mod "Alton Indiana".
Great work! Very nice... but freezing/crashing again! >grrrrr<

So: what I did was install the Unofficial FO3 Patch.
(Yes the one that has not changed since ~2010.)
It contains modules that detect and install for all five DLC.

Ran BOSS again. Everything sorted nicely including the Alton mod...
BOOM! Solid again.
This is my experience - just my $0.02 worth.

So not only is the Unofficial Fallout3 patch not extinct - it actually made my 'modded' game playable (if you count solely this one Quest mod, though it is large, as a modded game).
In essence I have played the whole game plus DLC, THEN installed the Unofficial patch, heheh.
Maybe you guys can be smarter, and install it right from the beginning...


PS.
CCNA if you read this
I love that guy Koroush Ghazi on TweakGuides.
Very smart fellow! I heard NVidia actually hired him?
Anyway I saw you linked to him - not sure if he lists this tweak specifically?
Point is: I could not remember the exact syntax of the tweak, therefore could not be sure.
But it's definitely the two-line item I posted (above).
Regards

I will talk to the Admins, as I am not allowed to sticky anything myself. However, I am considering adding this, and some other things to the sticky.

The other thing that really helps Fallout 3 or New Vegas if your using Keyboard and Mouse is to disable the gamepad and rumble (New Vegas) in the INI and the Rumble in Fallout 3.

Also, Fallout 3 should be installed in a non stock location, unless you want to turn off the UAC or run the game as an Administrator.

Compatibility mode can also help.

Windowed mode can help with performance issues, if it works better, there is a mod to remove the window border.