The first thing you need to do is get yourself over to HLP and the SCP website and download FS2_Open.
FS2_Open is the result of the communities work with the FS2 source code. Basically they've taken the 7 year old game and brought it bang up to date.
Basically you want the exes from
this thread on HLP and the media VP files from the
official SCP website. (ZPack contains all the other VPs so you only need to download that one really).
Quick question though. Do you have FS2 or FS2:Colossus? Cause the latter isn't the full game, just the first 10 missions or so.