Sorry, I should have be more precise. I'm using version 1.39 on Windows XP.
As for the files, I edited, in the installation directory, "hwconfig.txt",and also "settings.txt", so the game would always show stress when entering simulation mode. But for both, whatever I do, the changes are not taken into account and are cancelled after I close the game.
And I think I should also mention I bought the game through the infamous paywahteveryouwant.com site. Maybe that version was different.