How to open a Z01 file
Most archiving software such as Bandizip usually creates one ZIP archive when compressing a file.
When a separate configuration is applied, however, the archiver can split a file in several parts and create "z01", "z02", ... files besides one "zip" archive.
Split-compression is a compression method in which a large file is compressed and split in smaller files. By nothing but opening a ZIP archive with Bandizip and decompressing it, the original data which is stored in "z01", "z02", ... files is also decompressed automatically. The z01 file alone need not and cannot be decompressed.
Bandizip allows you to open a ZIP file (with a Z01 file) and all other split-compressed files.