BI doesn't come with anything in its folder packed, but the RTW side of the installation still uses packs - and the BI part looks up some of those (for instance the UI pips for the religion icons)

Most things for BI though - like unit textures - you'll be able to find in the BI/data/... folders without unpacking.


Not sure about vista - if you look in M2TW forums I think more has been mentioned there... only bit I do know is that if you installed RTW to its default installation path in C:Program Files, then vista doesn't want to let you alter things in there initially.