RAR archive of 1.76 MB for Compal board LA-D991P, without any laptop brand, model or contents given in the name. Compal uses the LA-xxxxP numbering for motherboards built for several brands, so the title block or PCB marking reveals the exact project. Extract it to see whether it holds a schematic, boardview or BIOS. Diagrams help trace rails and locate parts, while a firmware image must be checked against the flash chip size, with the original chip backed up before writing.
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 @cyberlanelectonik. 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.