I'm having difficulty getting Microsoft's Backup program (Win2000 Server) to function reliably. I replace tapes each weekday evening and my daily backups are executed properly...until the weekend. As I am not in on the weekends to change tapes, I have intended to have the tape which is used for the Friday night backup to be overwritten each night for the Saturday and Sunday night backups. However, every Monday morning I get the error that "backup was not performed because no unused media was avaialable". I have looked the Backup's Options, but have not found any setting to alleviate this problem. Does anyone know what I am doing wrong?