you need to use some third party products that will do this for you.
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For 3rd party products...follow these links
http://www.dreamincode.net/forums/topic/40261-pdf-library/
[http://www.dreamincode.net/forums/topic/40261-pdf-library/
]
http://stackoverflow.com/questions/2083387/c-pdf-to-word-programmatically
[http://stackoverflow.com/questions/2083387/c-pdf-to-word-programmatically
]
http://in.answers.yahoo.com/question/index?qid=20100821115721AAClSKz
[http://in.answers.yahoo.com/question/index?qid=20100821115721AAClSKz
]
The present possibility is to use a library to convert PDF to DOC, also remember these are from 3rd party or freeware.
Here is a tutorial how to use it to convert your own document to pdf files within your own application
Tutorial
http://itextsharp.sourceforge.net/tutorial/index.html