Thanks for the message about BIOS.
I won't disable my integrated card because other programs might be using it.
But, what's interesting. My Nvidia Program doesn't allow me to set a rule for lithtech.exe to launch it always via normal videocard. But what's more interesting, after I have launched the game via my Geforce videocard (through RIGHT CLICK - launch with...), I now don't have problems with black screen even launching with my integrated card.
I might be mistaken whether I always launch the game with my normal card or not, but nevertheless, it's not a big deal now when I can launch the game manually with the Geforce card.
I hope everbody who has this problem will be able to use this little trick to enjoy playing normal M&M 9)