I am going to provide as much detail as possible. When I first bought the game I was using P4 3.6Ghz successfully after a lot of work and play with drivers and codecs. My board died so I built a new system with an:

CPU: i7 870 (has 4 cores each with hyper-threading so it as seen as having 8 cores)
Memory: 8GB Kingston (Dual Channel) 2 Chips
Motherboard: P7P55D-E PRO
Video Card: XFX Radeon 4890
Sound Card: Ceative 2ZS Digital Audio (Old Sound Card)
This system is not overclocked(OC), but it does work with it as I had tested it.
I have played over 8 hours straight after applying the fix and many times since at varying intervals without a single crash.

The only issue I had was getting the right combination of codecs working together. I am not saying that you don't need to update drivers because you do. However, I was running into the issue of random crashes in small rooms, crashes to desktop (CTD), and some other weird stuff.

Prior to the fix I had several combination's of codecs on my system and discovered that they were not working right. This discovery was made by having some sluggishness in Windows 7 the operating system (OS) itself as well as videos and some other codec dependent things that I use.

I found that none of the codec packs work successfully with this except these two together. That is:

XP Codec Pack 2.5.1

http://www.free-code..._Codec_Pack.htm

ACE Mega codecs pack (Yes this is an old codec pack, but it has a lot and it works):

http://www.free-code...CoDecS_Pack.htm

I tried everything else CCCP, Windows 7 Codec pack, K-lite (32 and 64bit), and a bunch of others with combination's of them together done in various orders.

To work Fallout 3 successfully do the following:

1) Update all your drivers on everything.
2) Install XP Codec Pack
3) Install Ace Mega Codecs Pack (with everything checked) accept:
A) Fingerprinting
4) After successful install of Ace open it up and make sure everything is checked (Codecs and Filters) then apply.
A) Some items will uncheck after you apply it. This is due to incompatibility with one another (don't worry about it that's fine)

The game will work or not work depending on the hardware you have. As the game and your hardware can be funny about working with one another, but I am very confident in saying that this is the true solution. So, be prepared to go back and forth in and only in Ace Mega Codecs Pack and checking and checking multiple combination's. This may take you several hours if my specific setup does not work for you. I know this because there was a different combination for the P4 system I was originally using and it took a long time.

And no I did not use and other fixes to get this working. So don't mess with the fallout.ini file its fine. There is no leak that is bogus and there is no problem with multicore processors.

It is just the codecs and filters.

BTW: My technical expertise on a scale of 1 to 10 is a 10 so feel confident about this solution.

Ask question and I will try to follow-up every now and again.

Happy Gaming.

Fallout 3 Rules!!!

Post so nice, you made it twice? We'll close this one.

Hmmm, some other moderator accidentally deleted the duplicate topic I left open, so I will reopen this one. Sorry for the confusion.