Starting fo4 with F4Se in full screen. causes it to either kick me off the game screen or window it to the size of my palm.Tryed windowed with and without borderless. i

[LoneWolfCade]

[Samuraitech]

You may need to check your Fallout4Prefs.ini file.  Under display look for :

iSize H=1440

iSize W=2560

These are mine.  Set yours for desired horizontal and vertical resolution.

 

You can also download BethINI.  It is a utility for editing your .ini files.  Good for users who may not know what to manually change in these files. It does it for you.  It is a must have tool in my opinion.  Works for most if not all Bethesda games.  Don't use it while MO2 is open if you use MO2.

 

My .ini files are located under Documents\My Games\Fallout4.  Make sure you back up the originals before you edit.  I think these files are created when you first launch F4SE.

I am using MO2 as a mod manager so you can edit the .ini files from within MO2.