RAR archive of roughly 1.32 MB labelled for the Intel D425KT desktop board, a compact Atom-based mini-ITX motherboard. The name gives no document type, revision or version, so the contents have to be inspected after extraction; at this size it most likely holds a BIOS image or a small set of service files. If it is a firmware dump, read and save the existing SPI chip contents with a programmer first, and confirm the image size matches the flash capacity before writing anything to the board.
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.