The backup files are stored in c:\woopos\backup folder. The system will keep 35 daily back-ups, 20 weekly back-ups and 20 monthly back-ups by default. The older files will be deleted automatically. If you have 100GB of hard drive space, the back-ups should never fill up hard drive space. We can adjust the backup copies number if needed. You will get a warning message when the hard space drops to less than 4GB. You can manually move backup files to external hard drives.