Archive for the Lenovo C260 all-in-one desktop, stored as a 2.64 MB RAR file. The name gives only the model, so the contents, likely a BIOS dump or service data, need to be checked after extraction. If it is firmware, it would be written to the SPI flash with an external programmer to repair a machine that fails to boot. Before writing anything, read and save the original chip contents, and compare the image size with the capacity of the flash chip on your board, since a wrong size will not fit.
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 @hrtechno. 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.