Compressed file for the MSI MS-7511 motherboard, version 1.3, 1.04 MB in RAR format. The name gives no content list, but it likely holds a schematic for that board revision. Several MS-7511 versions exist, 1.0 through 1.3, so check the version on the PCB. A technician would use it to follow power rails, check component values around the CPU VRM and chipset, and locate the BIOS chip and its supply when troubleshooting a dead 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 @schematicslaptop. 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)