An archive of repair files for Lenovo hardware (board NM-C421). Shared as “NM-C421 1.0.zip” — a .zip file, 4.90 MB.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @schematiclaptopramkushwaha. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.
Built-in OS tools7-Zip