ZIP archive for the Asus P552LJ notebook, 120 KB in size, with no document type stated in the name. The small size suggests a boardview or another compact service file rather than a full schematic, so extract it to see what it holds. Compare the model and board revision silkscreened on the mainboard with the file before using it. Boardview data for this laptop would let you find component positions, measure test points and follow nets, while a firmware image would need backing up the original SPI chip before any reflash.
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 @cidschematicandboardviewofficial. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.