Do you have the of this file saved in the same folder?
This is the "sequence number." It tells you that this is the first part of a much larger file that has been sliced into smaller pieces. Why do people split files? KR5.7z.001
You cannot open "KR5.7z.001" on its own. Because it is only the first slice of the "data pie," the computer needs the rest of the pieces to reconstruct the original file. Do you have the of this file saved in the same folder
Never change the numbers at the end of the files. The software relies on that exact sequence ( .001 , .002 ) to know which piece comes next. KR5.7z.001