ZIP package of 3.03 MB for the EG50-KB design with Wistron board number 12253-3M, plus the code 4ZK14. Wistron identifies its boards with a five-digit project number followed by a revision suffix, here -3M. The 4ZK14 token is probably an additional project or part reference. Such archives usually carry the schematic and possibly boardview, useful for tracing power sequencing, finding test points and checking shorts. Make sure the number and suffix on the PCB match before trusting 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 @ITHINKHS. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.