: This often appears as a naming convention for the first video in a series or as part of a file fragment (e.g., .z01 or .001 ).

: You can use the 9zip app mentioned in your query, or standard alternatives like 7-Zip or WinZip .

: This is a specific file compression app for Windows 10 that creates .zip archives and extracts formats like .rar , .7z , and .tar .

If you have a file or a set of files with these labels, they are likely parts of a larger video file that was "split" to meet upload size limits. To open them:

: A common format used to compress multiple files into a single, smaller package for easier sharing. How to Handle These Files

: Locate the file ending simply in .zip . Opening this main file will usually trigger the extraction software to automatically pull data from the other numbered segments.

: Ensure all numbered parts (e.g., part1 , part2 or .z01 , .z02 ) are in the same folder .

Do you have in your folder, or are you seeing an error message when trying to open one?