Boardview for MSI board MS-9819, compressed into a 757 KB RAR, with no revision or product name stated. Boardview data maps components, pins and nets onto the PCB layout, allowing quick location of test points, connectors and the parts sitting on a shorted rail. After extraction it opens in OpenBoardView, FlexBV or a similar viewer depending on the format. MS-98xx numbers are used by MSI for server and industrial boards, so compare the marking and layout of your PCB with the file before relying on designators.
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 @IT_SERVICE_WORLD. 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.