Most new PC’s do not come with a floppy drive – they have a CD burner, and a USB port that will take a memory stick (or card).
If you want to use CD’s for backups, you need to be aware that, at present, applications (programs) running under Windows cannot backup directly to the CD.  This may change in time.

You need to set up a folder on your hard drive for backups.
On the EasyBooks Database Backup screen click on the Browse button to find and highlight your new folder.  Click OK and then complete your backup.
From there, you will need to know how to operate your CD burner to copy the backup file to a CD.
Please consult you software manual or software help files if you are unsure how to complete this task

If you have a USB memory stick, you can set up folders on it like you would on your hard drive because it is in effect a removable drive.  By setting up a series of folders you can back up into a different one each time thus creating a rotation in the same way that you did previously with floppy disks.
With this done, you can tell EasyBooks to save your backup to the folder on the USB stick the same way you did with your floppy disk backup.