HP 15 notebook package for the Quanta U81 platform, 298 KB in RAR format. The small size suggests a BIOS dump or a short document rather than a full schematic. No complete board number is given, so check the DA… code on the PCB to confirm it is a U81 board. Before writing any firmware with an SPI programmer, read the original chip, keep the copy, and make sure the image size matches the flash capacity.
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 @hrtechno. 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)