Small RAR archive, around 860 KB, for the MSI MS-7435 board. The name gives only the brand and board number, so the contents could be a schematic, a boardview or a BIOS image. The size alone does not tell which. MSI's MS-7xxx numbering identifies its in-house motherboard designs, and revisions can differ in layout. Check the revision on the PCB before trusting component positions. For BIOS work, dump the original chip first and make sure the file matches the flash capacity.
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.