RAR archive for the P8H61-MX desktop motherboard, an Intel H61 chipset model; the file name does not state whether the content is a boardview, schematic or other repair data. The 391 KB size is small for a BIOS dump, which suggests layout or diagram material. Extract it to see what format is inside and pick a matching viewer. Before relying on it to trace standby rails, CPU VRM circuits or a shorted component, confirm that the model and revision printed on the board match the files.
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.