Not much to go on here. What system? Steam Deck? Previous installs?

When in doubt do the following:

• delete all files in C:\Users\Yourusername\AppData\Local\Fallout4
  
• delete all *.ini files (and only those) in C:\Users\Yourusername\Documents\My Games\Fallout4
  
• make sure there are no leftover mod files from previous installations in your Fallout 4 installation folder (usually Whateverdriveyouinstalledto:\SteamLibrary\steamapps\common\Fallout 4 )
  
• verify integrity of game files in steam
  
• try again

Make sure you run your pc at 100 % resolution and you do not use High DPI Scaling in windows.

*edit typo*

He forgot to add, nudge nudge.. Windows folder permissions, check that. Google.
If you've run/played it before/already then disregard my randomness guessing!

Generally, if a game only launches for a second and then closes meaning there is a setting that the game/system does like.

navigate to your Steam folder, then steamapps/common/fallout 4.
Then run "fallout4launcher"

go through the settings, turning everything off or low. make sure "weapon debris" is off in the advanced settings, and everything in there is off or low as well.

Now try the game, if it works. Go back in to the launcher and change things slowly back to something more reasonable/playable until the game runs.

but with out knowing more, such as your system specs -its hard to say what is going on.

it happened to me the same , was some missing microsoft updates
if you try to launch the game with the "fallout4launcher" (is in C:/program(x86)/steam/steamapps/common/fallout4" it should tell you what's wrong ,google it and you should hopefully solve it

Originally posted by ZoeCastill0:

it happened to me the same , was some missing microsoft updates
if you try to launch the game with the "fallout4launcher" (is in C:/program(x86)/steam/steamapps/common/fallout4" it should tell you what's wrong ,google it and you should hopefully solve it

good ol launcher trick