: Do not try to open 2.part15.rar . Instead, find the file labeled 2.part01.rar .

: Place all these files in the same folder. If any part is missing, the extraction will fail with an error like "You need to have the following volume". 2. Extract from the First Part

: Right-click the first part and select "Extract Here" or "Extract Files..." using a utility like WinRAR or 7-Zip .