WinZip is able to process multi-volume RAR files in their entirety as long as they have been saved in the same folder, no volumes are missing, the volume names follow certain naming conventions, and the extract operation is begun with the first volume.
All volume names following the newer naming conventions should have the extension .RAR, the same first name, and a middle name indicating the specific part number. For example:
Filename.000.rar
Filename.001.rar
Filename.002.rar
etc.
-or-
Filename.part01.rar
Filename.part02.rar
Filename.part03.rar
Multi-volume RAR files following older style naming conventions indicate part numbers in the extension beginning with .r00 but WinZip always expects the first volume name to have the extension of .RAR and all volume names to have the same 'first' name. For example:
Filename.rar
Filename.r00
Filename.r01
Filename.r02
etc.
Note that when you use WinZip to open one volume of a multi-volume RAR file that is not the first volume, you will see only the files that are compressed in that, and subsequent volumes. For example, if you open Filename.part03.rar of a 5-part RAR file, WinZip displays the files compressed in Filename.part03.rar, Filename.part04.rar, Filename.part05.rar. You will not see the files compressed in Filename.part01.rar or Filename.part02.rar.
