if you know any programs that open such file, please advise
I found this on Google, might be helpful:
http://www.ehow.com/how_4603679_open-rsd-file.html (http://www.ehow.com/how_4603679_open-rsd-file.html)
http://www.ehow.com/how_7714028_open-rosetta-stone-rsd-files.html (http://www.ehow.com/how_7714028_open-rosetta-stone-rsd-files.html)
http://answers.yahoo.com/question/index?qid=20090113105326AAg4nkQ (http://answers.yahoo.com/question/index?qid=20090113105326AAg4nkQ)
Good luck.