"set someone up"

what's the origin and meaning of the phrase "set someone up".it is used in the negative sense....quite unlike how u say "set up a business" or "set up a factory".anyone please?

It's the purpose of setting someone up that makes it negative. If you set someone up in order to knock them down, that's negative ("Set up like a bowling pin" as the Grateful Dead song Truckin' says). If you set up a business and try to keep it going, that's positive.