of course you know that windows comes with default security settings. neither steam nor the game installer nor the game make any changes nor bypass whatever antivirus, security settings, folder permissions, running programs you have on your system. up to YOU to manage all that for this game and any other game/app you install.

if the launcher does not appear try looking in folder
c:\users\yourWindowsLogin\appdata\local\programs\cdprojekt\log
try REDlauncher.log but may be an error msg in the others

game launcher needs to create folder
Documents\My Games\The WItcher 3
folder should contain files dx12user.settings or user.settings input.settings profile.settings
after game launcher runs and you set your graphics settings
and after game starts your gamesaves folder.

if these files are missing

check antivirus log? might be blocking game/game launcher.

check windows security/controlled folder access.
if on add exceptions for game launcher/game.

running Windows One Drive? One Drive moves the ini/preference /settings files to the one drive. turn OFF one drive. uninstall it if not needed.

or if you need one drive, should be exclusion/exception option.
exclude the games Documents folder or tell one drive to leave a local copy of the files.
details in the one drive user manual

check windows event viewer and also windows reliability history.
might be a game crash event or system related problems.

maybe you have some non standard screen resolution/display scaling
try scaling 100% monitor=60hz fps=60 to get game going on standard settings

if you have an nvidia graphics card, run geforce experience then optimize the game with that then try the game. maybe the nvidia settings work better than the ones the game thinks you should have