What is a 7Z.001 file? A 7Z.001 file is the first part of a multi-volume .7Z archive. It is typically matched with other 7Z.### files, such as a .7Z.002 file, 7Z.003 file, and so on. 7-Zip creates a 7Z.001 file when you choose to split an archive into multiple volumes, using the Split to volumes, bytes: feature.

More Information 7Z.001 file shown in 7-Zip 7-Zip is a free archiving utility available for Windows. Typically, when you archive one or more files using 7-Zip, the program packages those files in a single 7Z archive. However, you can instead choose to package files in a multi-volume, or split, archive. Splitting files into a multi-volume archive can make them easier to store, upload, and download, since each volume's file size is smaller than a single-volume archive's would be. (For example, you can split what would be a single 80 MB 7Z file into eight 10 MB 7Z.### files.) 7-Zip saves multi-volume archives as a series of 7Z.### files. The first file in this series always uses the .7z.001 extension. The number of additional files included in a multi-volume archive varies, depending on the size of the files being archived and the volume size you've selected using the Split to volumes, bytes: feature.