Anonymous
Hi. How's IT going? --- The answer depends on how it's going: great, well, okay, terrible, etc.
choko_canyon
You left out the word "it", as in "Hi. How is IT going?", to which I might respond "Just fine, and you?"
Cogito
Well, it doesn't make sense.
If they said, "Hi! How's it going?" I would probably respond, "Fine, and you?"