Hi,
I just installed Skyrim legendary edition via steam. No mods.
When I first started the game I noticed that even though the windowed mode was unchecked, the game ran in a window fitting the whole screen. Well, maybe I could live with that.
But when I started playing the game it startede to CTD without any error message every time an autosave occured and when I saved manually. Pretty annoying.
So I checked
C:\Users\"Me"\Documents\My Games\Skyrim\SkyrimPrefs.cfg
to see that