RAR archive for the MSI MS-7364 board, revision 3.1, 1.08 MB in size. The name gives the revision but not the contents, which are likely a schematic or a BIOS dump at this size. Make sure the PCB is marked 3.1, because other revisions may use different parts or layouts. The MS-7xxx code follows MSI's desktop numbering. Before flashing, read and keep the original chip contents and check that the image size matches the flash capacity; schematics assist rail tracing.
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.