Hey, thank you. I' ll try it.
What I've done until now: 1) use DriverCleaner and
reinstall 84.56a driver; surprinsigly, RIDDICK goes, but HL1 still crashes. I'll finish a lecture and then run the memtest suggested by RingWraith (jbruneau, I'm not showing disdain to your idea...

).
What really surprises me now, is the difference in RIDDICK images between this 84.56a driver and its predecessor (84.56) - look:
These lights in the face of Riddick were transparent using 84.56;
These "shadows" are completely new;
And what the heck are these "body extensions"????
2) Update. No errors detected with memtest. CPU 37/40º (celsius) chipset 31/34º VGA 53º (GPU) & 50º (RAM), with ambience temperature at 24/26º. My VGA is modded (6800 gt to ULTRA), and overclocked (435/1175), but always did business with no problems at all.
