Compressed RAR package for the MSI MS-1251 board, roughly 807 KB, with no revision or contents stated in the name. MS-12xx codes follow the MSI notebook numbering scheme, so expect laptop board documentation such as a schematic inside. Unpack with 7-Zip or WinRAR and review what is included before planning repair work. Technicians use such files to follow power distribution, identify test points and check components around a fault. Compare the MS-1251 marking and revision on your PCB with the documents to avoid mismatched references.
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.