In this dialog you can choose whether to split the file according to file size (making each piece a maximum of 1420 KB to fit on a floppy disk, for instance), or split into a fixed number of pieces. You can also choose the folder where the file-pieces will be created. Click the Split button to split the file (the original file won't be removed or altered in any way).
A freeware assembler utility is provided, and copied to the same folder by default. To reassemble the original file, just start the assembler and click Assemble. You can even use this tool to join files that weren't previously a single file (such as joining MPEG files to create a single long MPEG movie). Just rename the files into a numeric sequence using Batch Rename and use the assembler to stitch them.