Each time you exit the program, Bid Central will automatically backup important data files. BC checks most active data files when opening them to see if any have become corrupt. If a corrupt file is detected, normally BC will restore that file from the backup file and you will never know there was a problem. If Windows shuts down while BC is running, BC will automatically close all open data files but it will not back them up. If you turn your computer off with BC running, it is possible that you corrupt multiple data files when could result in the upleasant task of doing a "clean install".