So just recently I purchased Fallout 3 GOTY from Steam. I installed the game, started running it, got through the vault and everything was fine and dandy. So when I reached Megaton, it started to just freeze randomly. You could hear people walking by and the music was still going, but the picture is still. I don't know why it won't work and I've tried a few things to fix it already, any advice?

Here are my specs for my PC

Intel Core i5 Quad Core @ 3.0GHz
8GB Ram (Kingston)
Gigabtye Radeon HD6850 1.0GHz 1GB
1TB Seagate Barracuda HDD

If anyone can link me to any useful help topics, or if this has been solved before, it would be appreciated to link to those!

Oh, and the Steam Overlay does not even work anymore, nor does Overwolf(Another overlay application)

Have you tried the quadcore fix?

Open up the .ini file located in My Documents>My Games>Fallout 3. *Do not alter the one in the actual game directory labeled Fallout_Default_ini*
In the FALLOUT.ini find the line

bUseThreadedAI=0
change the 0 to a 1

then below it add the line

iNumHWThreads=2

Holy crap, thanks! I tried to do that, but since I got this game from Steam, I thought I would have to edit the ini folder in the Steam directory! Thanks a lot!

No problem, glad it worked.