RAR archive of 426 KB named A7V333 with version 2.00, which corresponds to a motherboard model and probably a revision or BIOS version, though the brand is not stated. The name does not say what is inside, so extract it and identify whether it is a schematic, boardview or firmware image. If it is a BIOS file, save the original chip contents first and make sure the image size matches the flash part before programming. For documentation, check the revision on the board matches 2.00.
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 @cyberlanelectonik. 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.