First: It’s your own risk to make changes that way. On my side, it works.
Just rename 2 movie-files (EA-Logo + Trailer)!
So where it is?
C:\install-folder\EA Games\Command and Conquer Generals\Data\yourlanguage\Movies
Rename 2 files. Add “_old_…” to that file-names.
Now should the game starts much faster. You don’t need to watch the intro of the game and it starts directly by a click to game menu.