I had the same problem,i even did what you did, updated it but it still didn't work, so i started messing with the editor.ini's and that got me nothing. but i thought it was a .dll problem so i started replacing .dll for steam in skyrim. i started by replacing steam_appid.dll from portal 2 (because they are both steam games at about the same time) and that fixed it. its not video card drivers, its steam itsself. i cant believe bethesda didn't catch that.