Kerbal.space.program.2.early.access.part01.rar -

: You must have every single numbered part (part01, part02, part03, etc.) in the same folder. If even one "piece" is missing, the archive cannot be opened.

What are you seeing (e.g., "Unexpected end of archive")? Do you have an extraction tool like 7-Zip installed? Kerbal.Space.Program.2.Early.Access.part01.rar

: Files split into parts like this are commonly found on file-sharing or "warez" sites. Always be cautious of malware or viruses when downloading software from unofficial sources. If you are having trouble opening it, let me know: Do you have all the other parts downloaded? : You must have every single numbered part