Ok. I have tried every single fix that I could possibly find and literally nothing is working. Every time I start up Fallout 3 the intro slides come up but it is extremely laggy and when I can start moving the cursor it is extremely laggy as well. I have tried changing the bUseThreadedAI to 1 and the cores to 2, deleting the intro scene, re-installing, windowed mode, changing compatibility to XP mode, putting the new dll file in, and none of it is fixing anything. If there is anything else that I can do please help me out. Thanks.

Oh, and just to clarify, my comp is able to run it. I can play Skyrim, New Vegas, etc. all on Ultra High.

you better just post your comp specs.

NVIDIA GeForce GTX 560

Intel Core i5 Processor

4 gigs of RAM

Windows 7 Professional 64 bit

Not really sure what else to put...

Here's the dxdiag from my comp.

Add this "/dc787d6f91709ad08a2c693d09aba8b2" to the end of "gyazo.com"

Add this "/6d985a1608524dfa8d8e2fc29b28537a" to the end of "gyazo.com"

And if it is of any help, I managed to get through the laggy menu and was able to play the first part of the game flawlessly without any lag. When I got to age 19 and I went into the Vault 101 atrium it began lagging again and it is still lagging with my in the Wasteland.

Here is a video of what is happening: youtube link - /watch?v=4QME2nwWm1Q

And here is the "Canyourunit" for Fallout 3 on my computer: Add this "/97dbceb73180e485c6e39748be010ac5" to the end of "gyazo.com"

You have already done the multicore tweaks, now do this:

Alright, in my C>Program Files x86>Steam>SteamApps>Common>Fallout 3 goty I changed the controls to what you posted but in the Fallout Prefs in that location I couldn't find the "bGamePadRumble". However, in Documents>my games>Fallout3 I did find the "bGamePadRumble" and changed it to 0 and I also changed the controls in that location as well but the game is still extremely laggy as it is in the video. Should I copy and replace the Fallout Prefs from my Documents to the Steam folder? For some further verification if it helps, I downloaded Games for Windows LIVE which did nothing and I also tried to movie the Fallout 3 goty folder out of the Steam folder and put it in a new "Games" folder in my C drive which made the game un-launchable. However, when I did move it and ran the Fallout3.exe as Admin it launched but lagged the same way as it did in my video.

You may have to change the default files, sometimes they will over write the changes you make in My Documents.

Just to note, if you hose the default files you have to reinstall the game. So, make back ups.

But, since you just dragged your install to another location, all the mod tools are going to be confused about where things are, and you have a mess on your hands with mods. So, a reinstall may be the ticket here.

FAllout 3 should never be installed in any version of Program Files. Instead, make a directory called C:\Games\Fallout 3 and install it there. Even better, move Steam to C:\Games\Steam (instructions at their site for this, it's easy) and then all your Steam Games will install there. You can also create an additional Steam Library in C:\Games if you don't want to move your existing Steam install.

Alright, I correctly moved my Steam folder out of Program Files and now everything is in C:>Games. I re-installed the game, did all the fixes again, and it is still doing the same thing. Just to note, it very rarely crashes so that's not the issue. The lag is just really bad on the menu and when you turn 19, go the wasteland, etc.

Did you disable the gamepad and the rumble, in both the default and derived files?

Try a strict clean boot, as some programs running the background can cause stuttering. Antivirus, IM's and Media Players are known culprits.

Do you have anything Asus? The GamerOSD and the Xonar are known problems with this game.

http://support.microsoft.com/kb/929135

If these two things don't fix it, then your going to have to chase down codecs. I will find the thread that talks about how to do this.

Edit: I can't find the thread that's here, but see the third post in this thread for the program

http://www.gamespot.com/fallout-3/forum/music-wont-play-at-all-54229184/

Also, try Windowed Mode, that can help. If it's better, then there is a mod to remove the border.

YES!!! Turning off the Arcsoft sound codecs did the trick. Thank you so much!

Awesome, glad it's working.

For sure all the other things you have done have made the game run better than it would have if you had just disabled that codec from the get go. However, for other's reading the thread, there is a way to see which codecs are causing the problem, so you can keep the ones that are working.