How to fetch data from crashed OS

Hi I have a dell Vostro laptop with two operating systems in it one is server 2003 and another is windows 7. all of a sudden windows 7 has got crashed which has all my data and the data is not reflecting in server 2003.
I heard that there is a way to fetch the data from remaining 2003 OS but have no idea on that so please could any one help me on this.