Excellent, thank you, just what I wanted to know. And yes I am still paranoid, (that's why I started using xxcopy), and will investigate using Sync too. Aside from copying the database to the same disk, I also regularly clone the disk, and copy both Master and Backup copies of the database to a NAS. I'm paranoid because the database represents about 20 years of strenuous personal effort tracing my family history. Losing it would be unthinkable.