Boardview for the MSI MS-7757 desktop motherboard, version 1.0, packed in a roughly 1 MB RAR archive. MS- followed by four digits is MSI's own board numbering, used for its desktop mainboards. Once extracted, the layout loads in a boardview program such as OpenBoardView or FlexBV, showing each component's location, pin nets and test points on both sides. It helps with tracing VRM and standby rails or locating a shorted capacitor. Verify the version printed on the PCB matches 1.0 before relying on it.
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 @BoardSchematic. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.