Well, what exactly does "doesn't work" mean? It'd be helpful to know what happens.
Does the game run?
If so, does it crash or run improperly?
If not, do you get any errors? Also...
Can you install the game?
If so, did you install the latest patches?
If not, again, do you get any errors?
I don't know what policies Sierra might have these days, but maybe the game only allows one account per product key. There might not be a legal way to do this (it's a bit of a gray area).