Tools like WinRAR or The Unarchiver (for macOS) can also extract .7z files.
If an application (like Calibre) does not recognize .7z , you may need to unzip it first and re-zip it into a .zip format. If you can provide more context, such as: Where did you download or receive this file from? Irk17.7z
If you get a "Can not open file" error, the file may be corrupted, incomplete (if part of a multi-part archive), or you may need a newer version of 7-Zip. Tools like WinRAR or The Unarchiver (for macOS)
Here is a general guide to handling .7z files like Irk17.7z : What is a .7z File? the file may be corrupted
Download and install the official 7-Zip application to manage these files on Windows.