Put your DVD into your DVDROM player in the PC, run DVD Decrypter, select IFO mode and in the information screen it will tell you all the Regions that DVD supports.
There is no specific All Region format (there is no Region 0), just some DVDs can be played in all Regions (ie. supports Region 1,2,3,4,5&6). Just about all DVD Players in Australia are Region free so they can play any DVD purchased in any country in the world.
A substantial amounts of DVD's here in Australia (PAL Region 4 ) are infact Region 2 & 4 even though the package only says Region 4.