: Reaching "Part 18" suggests this is a heavyweight download. If each part is roughly 2GB (a common limit for hosting sites), the total package could easily exceed 40GB–60GB.

: You only ever need to right-click and "Extract" Part 1 . The software will automatically find Part 18 and the others to complete the job.

: Ensure all parts (part1 through partX) are in the same folder before you try to open the first one.