If this works does it save my files

Hello,
I just upgraded my software. (yes I am way behind on upgrades because of this very reason) I was afraid that I would loose data. Now, I cant accesses my old admin because of a file vault error. Does this reset the file vault also? I am in the middle of grad school and about to loose a ton of data if I can access my account. I am very upset. I created another user but, still cant log into my old account. I have contacted Apple and they will not help me. Do I uninstall Snow leopard to be able to access filevault again? Help!
Thank you,