RAR archive for the MSI MS-7500 motherboard, revision 0A, about 1.31 MB. The name gives the board number and revision but not whether the files are a schematic, a boardview or firmware. MSI writes revision codes such as 0A or 1.0 on the PCB next to the MS-7xxx number, so check that the board in hand is also rev 0A before using part references or test points. Extract it with WinRAR or 7-Zip, and back up the BIOS chip before flashing any image inside.
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.
7-ZipWinRARThe Unarchiver (macOS)