Command line, batch, or drag and drop modes. If file name ends in dot and digits, program seeks other files in same series and joins them. Otherwise, program divides file into pieces of user specified size, and builds optional *.bat file for rejoining. For large files, program can join pieces many times as fast as the *.bat file. Program has been tested on *.exe and *.zip files above 21 Gigabyte size. Only limit is available disk space.