Notezilla keeps 5 copies of backups. And it takes a backup at startup. You can only change the location of Backup folder from preferences (Advanced tab). To access Notezilla 's Preferences, right click on Notezilla icon and choose Preferences from the menu.
I am not sure if you are syncing notes with our cloud system. Usually, that serves as a backup for most customers and it is easy to setup any device with your notes by just downloading the notes from the cloud.
I suggest that you try the sync feature of Notezilla that will allow you to sync notes with other devices and PCs. Right click on Notezilla icon and choose Sync option to create new sync account. You can also try our Android/iPhone apps that will allow you to access all your notes.
You can also use your own backup tool to keep multiple copies of Notezilla data file.