This was very helpful. But, it does not answer following 2 issues. Any answers on this front would be appreciated:
1-Are compatability downloads and features needed, and do they work, with MAC Office 2003?

2-When you first load 2007 Office to a PC that had pre-Office 2003 [probably 2002?], will old Word and Excel files be immediately viewable in 2007 Office or must any special steps be first taken? Should any such steps be taken BEFORE installing Office 2007