Step 1) You will have to go to Documents\My Games\Fallout4 and open Fallout4.ini
located at C:\Users\[NAME]\Documents\My Games\Fallout4\
Scroll down to [Controls] and add bMouseAcceleration=0 under it


If you want to be 100% sure it worked, add this:

Step 2) Now open up Fallout4Prefs.ini (in the same folder as the previous step) and add under [Display] bForceIgnoreSmoothness=1 (There's an error in the picture, and it says =0, replace it with 1.


Step 3) Next thing is in another folder, locate your Fallout 4 installation folder (usually in program files, or where you've installed steam by default, or your custom fallout 4 folder) a great way to find it is by right clicking Fallout 4 on steam, properties, local files and click browse local files, locate this: Steam\SteamApps\common\Fallout 4\Fallout4 and open Fallout4Prefs.ini and add bForceIgnoreSmoothness=1 under [Display]

Step 1)
Documents\My Games\Fallout4 and open Fallout4Prefs.ini

Find iPresentInterval=1 line and change it to iPresentInterval=0


Step 2) If you're still having issues, try capping your fps down to 60 and turning your monitor down to 60hz
For AMD cards users, use the amd radeon software, you'll have to add fallout 4, turn on upgraded vsync, turn off amd freesync and turn down the fps to 60

For NVIDIA cards users, Download Rivatuner
You will have to cap your fps to 60, unfortunately fallout 4 engine *just like any other bethesda games so far, cannot be played over 60 fps without having issues with the game (a famous glitch from skyrim is caused for having over 60 fps
https://www.youtube.com/watch?v=xRFXjPwGc9E
Anyways, once you've downloaded rivatuner, it might be on your "mini" taskbar

Open it and you will see this

Click add and find fallout 4.exe

Finally, set the fps to 60 and the detection level to medium and let rivatuner opened everytime you play a bethesda game (this also fixes older assassin's creed games)

One last thing, if you've capped your FPS to 60, and you're still having issues on a 144hz monitor, try lowering your monitor refresh rate to 60 so it matches the maximum fps

Problem fixed? Drop a like, and share this guide to your friends!

Still having problems? Comment down bellow and i'll try to help you as much as I can, otherwise reddit is a great place for fixes

Enjoy your Fallout 4 adventure!