RAR archive, 1.84 MB, tied to the MSI board MS-7028 and otherwise undescribed by its name. Expect schematic, boardview or BIOS material, and confirm which after extracting. A schematic lets a technician follow the path from the ATX connector through regulators to the CPU and chipset, which helps find a shorted rail or a missing enable signal. MSI assigns the MS-7xxx numbers to its own motherboards, so check that the silkscreen matches, including revision, and dump the original BIOS before writing anything new.
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.