Small 867 KB RAR archive tagged for the ASUS X540SA laptop; the RG suffix in the name is not explained, so the exact contents are unclear until it is opened. Files of this size for ASUS boards usually hold a BIOS image, a boardview or a short repair guide, so check what is inside before planning a repair. If it turns out to be firmware, dump and keep the original chip contents first, and compare the board revision printed on the PCB with any revision mentioned in the extracted files.
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.