RAR archive for the H61S1 board, marked mp1.0, 2.57 MB. The mp token probably refers to a mass-production revision, though the name itself does not explain it, and the contents are not listed. An Intel H61-class desktop board is implied by the model. A RAR needs WinRAR or 7-Zip to open. If it holds a BIOS image, compare the revision on the PCB, back up the current flash with a programmer, and confirm the image size fits the chip 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 @laptopchiplevelrepair. 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)