Boardview for Lenovo motherboard NM-E441, made by LCFC, Lenovo's own ODM, which marks its boards with NM-prefixed codes. The name gives neither the laptop model nor the revision, so compare the number and revision printed on your PCB with the layout before use. It is a 4.82 MB RAR archive. In OpenBoardView, FlexBV or a similar program it helps you locate components, follow nets, trace power rails and find test points when diagnosing shorts, dead regulators or missing voltages.
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 @BoardSchematic. 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.