Archive named ASUS A7K, but only 71 bytes in size, far too small to hold a schematic, boardview or firmware image. It is almost certainly empty or a broken placeholder, and the name gives no other detail about its intended contents. Real service data for a model would normally take at least several hundred kilobytes. Try opening it to confirm, but do not expect usable material, and look for a complete copy that matches the board number and revision printed on your PCB instead.
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.