Kdmvarset.zip.001

7-Zip is the most highly recommended tool for this format. You can right-click the .001 file, select "7-Zip," and choose "Extract Files".

The file is the first segment of a multi-part split archive. Large datasets or software packages are often split into smaller "volumes" (like .001, .002, etc.) to make them easier to download or share on platforms with file size limits. kdmvarset.zip.001

If all parts are present but extraction fails, one of the segments may have been corrupted during download. Many users use tools like QuickPar to verify file integrity if parity (.par) files were provided by the uploader. 7-Zip is the most highly recommended tool for this format