There are various problems in different stages of games. For instance, fallout 3 crashes at the start of the game. If this is your case then try the following solution.
a) Go to Start Button on the desktop
b) Select Programs
c) Navigate to ffdshow folder
d) Now click on the "Audio Decoder Configuration"
e) Find here "Don't use ffdshow in" and check it
f) Check that box and underneath it lights up on a check. You should now add "fallout3.exe" without quotes. If there is already something written then put a semi colon ( after that name what you see. Now write fallout3.exe without spaces. The valid entry would be "explorer.exe"
g) Click OK and start Fallout 3
You can apply these steps if your Fallout 3 game crashes randomly.
If you have a quad core PC and you installed the latest patch and game started crashing then you must use following instructions to resolve it.aa
Open fallout.ini file and find bUseThreadedAI=0 and change it to bUseThreadedAI=1. After doing this you should insert another line to write iNumHWThreads=2.
If you see there is still crash then instead of iNumHWThreads=2, change it to iNumHWThreads=1
Always remember that Windows 7 operating system takes more RAM than previous version, so upgrading your RAM to 2GB may resolve your issues.
To Fix Fallout 3 game crashing issue and other common PC problems, experts recommend using Best Registry Cleaner and PC Optimizer software. You can find the latest version of the product on official website of RegInOut.