You must have part01 , part02 , and any subsequent parts (like part03 , part04 ) in the same folder. Extraction Software: Use a tool like 7-Zip or WinRAR .
Usually includes "New Frontiers" expansions or weekly "Week [Number]" updates (Icarus is famous for its consistent weekly content drops). ICARUS.v1.2.12.100160.part02.rar
Optimizations for the game's demanding engine. You must have part01 , part02 , and