Rar archive named P8H61 100, tied to the P8H61 H61-chipset desktop board line; the trailing 100 is unexplained and may be a revision or a firmware number, so treat it with caution. The name gives no clue to the contents, so unpack and inspect them first. When writing a BIOS dump to the SPI flash, read and save the original with a programmer, verify the exact board model on the PCB and make sure the image size equals the chip 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 @boardview. 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)