Im a LE user, but its a general question i have to any one who could give me solution with that problem

Well, many rock bands dont use and dont care of keyboard sounds at live perfoms, but for instance Rammstein, Dream Theater, Type Negative has enourmous and kick ass sample sounds. My question is: does anyone knows how they controll all of these sounds libraries while doing live shows?? I know they have much more instruments than only my one LE, but if i had for ex. Laptop with storage of samples how to controll it? how to "exec" right samples in right timing? are there any programs for samples on PC??. "Devil is Hidden in Details" so i want to sound nice at all the time, not only on the record (on CPU everything can be done) but it has to be played well on live too as well.
Please reply me some tips, or how You do that, if anyone did so

TIA.
Best regards
James L.
Poland