Service archive for the MSI MS-7647 desktop motherboard, revision 0A, roughly 1005 KB in RAR format. No other details are given in the name. Contents of this kind are normally a schematic or boardview used during component-level repair. MSI marks the MS-xxxx code and the revision on the PCB, often between the expansion slots. Match both before relying on the drawings to trace standby voltages, the Super I/O power-on logic, or a short on the CPU core rail.
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)