A small RAR archive of roughly 100 KB whose name points to the A78M-E motherboard at revision 1.03A; the name does not say whether the contents are a boardview, schematic or firmware, so inspect it after extracting. A78M-E matches ASUS desktop board naming, though no brand is stated in the name. If it holds a layout file, a boardview viewer will show component locations and nets for fault tracing. Always compare the revision on the PCB with 1.03A before relying on the data.
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 @schematicslaptop. 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.