That's what the back-up option does... ;-)

Unfortunately, the Poser SR1 read me does not say, where to find the back up files.
But I am sure, they are there.

Try doing a search for LibraryPrefs and look at the file location.
They may have been moved to a specific back-up folder somewhere close by.

If you can't find them, then there is no way of getting them back, short of a system restore...
(if you did a system store prior to installing the SR)

 

Yesterday's the past, tomorrow's the future, but today is a gift. That's why it's called the present.