RAR archive of 879 KB for the MSI MS-7260 motherboard, revision 10, usually read as version 1.0. The name does not say what is inside, so extract it with WinRAR or 7-Zip and identify whether it is a boardview, schematic or firmware image. MSI uses MS-7xxx codes for boards it engineers itself. Check the revision marked on the PCB before relying on component positions, and if a BIOS dump is present, read and back up the original chip with a programmer first.
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)