An archive of repair files for ASUS hardware. Shared as “ASUS M5A78L-M LX V2 (REV X.XX).rar” — a .rar file, 821 KB.
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 @Satale_bios_esquemas_Laptop. 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.
7-ZipWinRARThe Unarchiver (macOS)