Make images, ghost, acronis, macrum reflect, its all good. Images are copies of the entire drive you store externally. Then even if a steamroller hits your hard drive, pop in a blank drive in your computer and run imaging software and re-image and you're back in business.
I liked Ghost the best but they stopped making it. (Symantec bought it and became Norton and then discontinued).
Acronis true image rules, but it has a lot more options and not as idiot proof.