RAR archive of 2.97 MB labelled PA HM65 version 5.21, pointing to firmware for a board built on the Intel HM65 chipset, used in second-generation Core laptops. The brand and exact model are not stated, so identify the target from the board silkscreen or files inside. Small images like this usually suit 2 MB to 4 MB SPI chips, so check the capacity. Keep a backup of the original contents before flashing with a programmer.
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 @biositechyangiyer. 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)