OK! Don't panic! In my persona experiences, you also can still have chances to restore all your files, as long as they are not rewritten by anything new.
What you should do right now is to choose a proper data recovery program to restore all your inaccessible files back successfully.
But, if you really know a little about the data recovery stuff, you can read this thread to know the detailed steps:
http://forums.cnet.com/7723-7588_102-595975/any-suggestion-to-get-back-my-data-from-my-hard-drive/
Note: If you still want to save the memory stick, you'd better format it after the data recovery process.
Good luck!
My memory stick has encountered a really bad trouble. Every time when I tried to use it on my PC, it will ask me to format it. But, I know that the formatting thing will delete everything inside this stick. Please help me save this memory stick and inner files back? I am not so good at computer. So, if you could, I hope you can tell me the detailed steps.
Thank you very much!

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