Enderal SE
If you are talking about the Steam installation, open Data\SKSE\Plugins\SSEDisplayTweaks.ini , find the [Render] section, uncomment the lines
Borderless=true
Resolution=1920x1080
and set your own resolution.
The file i needed to edit was found in "Enderal SE\Data\profiles\Default" and is called skyrimprefs.ini
The default settings in skyrimprefs.ini were listed as:
bBorderless=0
bFull Screen=0
iSize H=1080
iSize W=1920
I changed bFull Screen=0 to bFull Screen=1 and saved and launched the game again and everything shows fine now.
Just wanted to pass this along in case anyone else needed to manually change resolution or change full screen option.