MSI laptop motherboard package for board MS-17731, version 1.2, in a 15.6 MB ZIP. MS-xxxx is MSI's own board numbering, and the trailing digit often marks a sub-variant, so match the exact number and the 1.2 version on the PCB. The archive size suggests a schematic and possibly a boardview, though the name does not confirm it. A technician uses it to follow power rails, check the GPU and CPU power stages, and locate components and test points.
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 @ITHINKHS. 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