Whimsey, r u on a Mac or pc?
On a Mac, there's no backup needed, as long as you store the download in "applications". It should automatically go to version 5 with current generations.
I'm not familiar w/ pcs, sorry.
On the other hand, I know it blows to start all over, but I've found that when I did, the "variety" was better (people choosing; store items, etc.)
Hope all goes well.