It appears that starting with Snow Leopard (maybe sooner) you cannot take a hard drive out of one Mac and put it in another one.
It won't boot ~ even if you used it externally to boot your Mac.
You get the folder with a question mark on it.
It seems the MacOS now ties hard drive serial numbers to the motherboard.
So, with each new installation of a hard drive … you have to install a fresh (authorized) copy of Mac OS X then do a migration of all your files.