My pen drive cannot be recognized now on any computer/laptop?

My PC used to detect my pen drive/memory but now for some time it has stopped recognizing it, infact now the pen drive cannot be recognized by any computer. I badly need to retrieve the data from it and if possible I would like to have my pen memory intact. can someone help me out, if so please write to me at drajaykay@rediffmail.com. i shall always be grateful to the person