I can install the 2008 version of pgf fine using package manager in Miktex 2.8.
However I need to install v2.0 as I need to do horizontally split nodes. I have downloaded 2.0 and unpacked into c:\texmf directory maintaining the package directory structure. I've added this to the the miktex roots.
I've pointed the package manager at every level within the directory structure and it always comes up with an error 'does not seem to be a local package repository'. Am I missing something?