"LSI1.part1.rar" is the first segment of a multi-part compressed archive, likely containing software, media, or large data sets. Because it is a "part1" file, it cannot be used by itself; you need all subsequent parts (e.g., part2.rar , part3.rar ) in the same folder to successfully extract the original contents.
Large files are often split into smaller "parts" to bypass upload limits or make them easier to share. LSI1.part1.rar
To "rebuild" the original file from its parts, follow these steps: How to open and extract rar files on Windows 10 pc? likely containing software