I would keep at least 2 images. On my desktop I keep about 20, will never go that far back if I need to restore, farthest I have gone back to restore was 2 weeks once, but on my notebooks I only keep about 4-5 images for each notebook, and rotate them, so they are on different external hard drives in case one fails.
Example USB drive 1, create an image to it, next time, use USB drive 2 and so on. This way if one drive fails you have a another copy, just to be safe. |