I just bought FO3 and got it to run on Win 7. But now it just "freezes" and i can?′t interact with the game anymore. When the crash occures and i was running in one direction, i just keep running, the npc?′s are still doing whatever they were doing, the sound also is still normal. When i alt/tab the game it switches to Pause, but i can?′t move the mouse there or open the console. This happens from 5-20 mins after starting everytime. I also noticed the fps increase when this happens, it goes from around 25-30 to 60-80. I already tried unofficial Patches, stutter remover, 4GB Patch, the .dll and changing the .ini files.

Did you follow all the install steps in the pinned thread? Including the Install Location?

http://www.gamesas.com/topic/1465357-installing-fallout-3-with-windows-78-and-xp/

I am not sure what you mean by all the INI fixes, you only need two of them to make the game run without locking up.

And, do you have any mods on the game?