Launcher settings keep changing to full screen suddenly.

[Chimp Factory [M04]]

I start the launcher and change the launcher settings in Options>TES3 Direct3D Driver Selection to window mode and hit Ok; launching game or going to options has it run or show fullscreen.

I was launching the game fine for many sessions in windowed mode [18+ hours worth]; and now it refuses to keep in windowed mode. Checked the Morrowind.ini out of habit and nothing for Window or Screen options.

Edit: Verified files, reinstalled, and did restart computer; no change

Edit2: Fixed
Ran Steam as Administrator and now its saving options again.

[Noémy | Damaranth]

This worked for me, thanks!