If your extraction fails, double-check that the filenames are identical except for the part number. For example: ProjectData.part1.zip ProjectData.part2.zip
You don't need to extract each part individually. Most modern archive tools handle this automatically if you follow these steps: PART1zip
To access the contents, you need in the series. If one part is missing, the file won't open. How to Extract "PART1.zip" If your extraction fails, double-check that the filenames