Close the Launcher and the game.
Delete C:\Users\%username%\Documents\Battlefield 2142\Profiles\Default\Video.con
As well as C:\Users\%username%\Documents\Battlefield 2142\Profiles\001\Video.con
Start the Launcher again, go into the Settings of the Launcher:
• check widescreen mode,
• uncheck windowed mode and everything else in the launcher settings,
then click "PLAY NOW" to start the game (it will start in fullscreen and hopefully without a black screen).
If it crashes to Desktop, go again into the Settings of the Launcher and enable Windowed Mode (800x600) and start the game again, tell us if you see any error messages being thrown.
(Edits added by Moderator S_h_a_r_k_93).