Open your "f1system" on your GP4 main folder and you'll have :
; Grand Prix 4 System File - do not edit
save_state_on_exit = true
install_level = full
minimum_allowable_version = 0
language_name = italiano
user_name = ""
animation_quality = medium
Change "italiano" of language_name in "english" (or another language)
That's all
Vous avez voulu Hollande et les socialistes, vous les avez !!! Au secours, la France est au plus mal !