eh ?
Acronis True Image is what i use.
http://en.wikipedia.org/wiki/Acronis_True_ImageIt copies an entire drive, verbatim, and saves it to a file. Then you can swap to a new drive, or if you fuck up, reinstall the image on the same drive. It's like rolling back a system, except it removes everything on the drive and replaces it with the image previously taken.
I used to use it for running trial software. Install it, take an image, when the trial expires, reinstall the image = new trial. It takes about 10 minutes to create an image, and 5 minutes or so to reinstall one.
I presume that's what the eh? meant.