I back up all my genealogy programs and data onto a CD every week or after an exceptional amount of data gets entered.
I also use the cd to update my UFT files on my laptop when I take it for research. Because I use CD-R and not CD-RW I need to change the attributes of the data files after I do the copying so I can use current data on the run.
I have only had to use the backup CD once when my machine froze up while UFT was open. No problem copying the entire data base into the same area over the old files.