MSI MS-7066 package stored as a RAR archive of 1.53 MB. The name offers no revision, firmware version or content description, so the files must be identified after extraction. Such archives usually hold schematics, boardview data or BIOS dumps for board-level repair work. MSI uses MS-7xxx codes for its desktop motherboards, printed on the PCB itself. Compare that revision with the documents, and if reflashing, read and save the original chip with a programmer and confirm the image size matches the flash.
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 @IT_SERVICE_WORLD. 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.