ZIP archive of 3.90 MB labelled LM91M-19V, which reads like a board or module code with a 19 V supply reference. The name gives no brand, device or document type, so the contents may be schematics, a boardview or a firmware dump, and you should inspect them before relying on any of it. A 19 V figure is common for laptop adapters and some monitor or TV power boards, but only the extracted files can confirm the target hardware. Match any board number inside against the markings on your PCB before use.
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 @gunvantrathore. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.