Hi Sandran
Without knowing what state you are in and what your connection to the person who died is, I can't answer specifically, as not everyone is entitled to a copy of a will.
If you are in NSW or Qld the NSW Succession Act 2006 sec 54 and the Qld Succession Act sec 33Z will quickly tell you if you are entitled to see any wills whether current when a person died or previous (revoked). I am not so familiar with other states. You can find legislation online at Austlii.edu.au
Have you tried asking the person who has the previous will if you can have a copy? If part of your question is whether there is some type of central registry of wills, no there isn't.