A split archive is like a puzzle; you cannot see the picture until every piece is present.
You can use 7-Zip on any computer, including a computer in a commercial organization. You don't need to register or pay for 7-Zip. How to Extract .7z.001 files - Microsoft Q&A
Look for files named 3carvideos.7z.002 , 3carvideos.7z.003 , and so on.
The software will automatically detect the remaining parts ( .002 , .003 , etc.) and stitch them back together into the original video files. Troubleshooting
Mobile users can use the RAR app from the Play Store to join and extract these files. 3. The Extraction Process
If you’ve encountered a file ending in .7z.001 , you aren't looking at a single corrupt file, but rather the of a multi-part compressed archive. To successfully open it and view the "3 car videos" inside, you must follow a specific process. 1. Gather All Parts