Service archive for the MSI MS-7829 motherboard at revision 1.1, a RAR file of roughly 1.18 MB. Its exact contents are not stated in the name, so unpack it to check whether it holds a schematic, a boardview or both. MS-7829 follows MSI's in-house numbering for desktop mainboards. Confirm that the PCB silkscreen shows rev 1.1, since component values and placement can change between revisions, then use the material to trace power rails, check the CPU VRM and locate faulty parts on a no-power board.
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.