If u r talking about DCs, better take system state backups & store then in HDD and burn a copy in dvd. Do not use non ad aware backup software as restoring that backup will cause a USN Rollback (in plain simple word ur screwed)
If ur talking bout workgroup desktops, then backup data to another HDD & also burn a copy in a DVD.
Hey friend you can also have another option to store your data offsite that means your data will get stored at another location on a remote server.
Data storage other than storage medias gives you more protection to your data from any kind of threat or virus. It is an automated method.