The software will automatically detect and pull data from the other parts to recreate the original file. :
: If the software asks for a specific volume, check that the file names are identical except for the numbers (e.g., ensure one isn't named real (1).rar by mistake). real_1.rar
: This usually means one of the parts is corrupted. If you are using WinRAR, you can try the "Repair" command. The software will automatically detect and pull data