Memory Stick Recovery Software Free

"I have a Sony memory stick which contains many important data including photos, videos, music and some documents and more. Recently, I was unable to access the memory stick normally because when I inserted it in my camera, it says memory stick needs to be formatted. If I inserted the memory stick to my laptop, Windows PC also reports that memory stick is not formatted do you want to format it now? If I format the memory stick, will I lose everything stored on it? However, how can I access the data if I do not format the memory stick? Can you tell me what to do to fix the error and get back lost files?"