System 800xA has built-in online backup tools that backup the application(s) but not the operating system nor any ABB or 3rd party software.
ABB recommend topping up the application backup with drive image backups after first having performed a "Maintenance Stop" which shut down all ABB applications. Remember that some software will still run, e.g. Oracle and MS SQL Server which may not accept "hot imaging".
I sincerely recommend performing cold drive imaging (with OS shut down).
I see no immediate use cases for Windows Server backup with System 800xA with the exception of domain controllers where the System State (Active Directory) can be backed up with Windows Server backup.