Documentation for the Sony VAIO VPC-CW series, built on the MBX-214 board and listed as M870 revision 1.0, packed in a 1.46 MB RAR. M870 is most likely the ODM project code for the design. The archive is probably a full motherboard schematic, useful for diagnosing power, charging and display faults by following rails and signals between components. Check that both the MBX number and the revision on the PCB match before trusting part references or measured values.
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 @generalschematics. 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.