Replace Backup file

I just downloaded Backup & Recovery 2013 Free and my system is xp pro with 2 internal drives (C 80 GB & D 160 GB) and an external drive (E 320 GB).
Due to how much computing I do, I prefer to do a full backup of C & D every night and replace the old backups.
When I started Backup & Recovery and started the process of creating backups for the C & D drives to E, I could not find any check marks to replace the old backups.
Please let me know if this function is available and where I might find it.

Thanks

 

Never mind. I found the answer from a previous thread.
Thanks anyway