You do need to extract each part individually. The software is designed to automatically "stitch" them back together.
: A popular, free, open-source alternative that handles multi-part RARs well. WinZip : Another widely used option for Windows users. 3. Extraction Steps SPECIAL1151_PACK4.part2.rar
Do you have of the pack, or are you missing Part 1? You do need to extract each part individually