Besides the built in option for creating full images I went with Acronis TI which reduces the sizes of images with a degree of compression as well as back up the main drive on two other completely separate drives in case one of those goes belly up. Other things are backed up externally to prevent any possible loss or to back up other systems along with a few laptops.
Even with all that you also have to take into consideration having a worthwhile av and antimalware detection system inplace that will spot bugs hidden in things you wouldn't expect to find any in like the zip files you download for some free utility that just happens to include some uninvited guest or crapware additive you don't want!
Sloppy backups can lead to major headaches where you can lose as much as if a drive or device decides to quit on you. I-Worms are the most notorious for recoding files when they happen to be a self replicator as compared to other bugs like data collectors you can burn off. The files that get recoded may not be able to restored to a a working state depending on how much of a change was seen. Other bugs simply make as much as possible unusable.
Hi there
Here's where W8 trumps W7 -- the built in Windows defender (re-named -- not the same as windows defender in W7) works extremely well and renders typical A/V software obsolete. (One of the few areas where W8 wins out). However if you install MSE on W7 that's probably just as good (or bad) as most AV software out there -- and of course a system should be CLEAN before it's backed up otherwise it's just junk.
MSE does Real time protection -- anything else is useless since with "after the fact discovery" you don't know exactly when the machine became infected or what the infection has done to the computer since. You should always in any case do a scan before backing up the system -- if infected restore from your previous good backup -- there is NO point using "cleansing" software as you could never be sure that its worked.
Cheers
jimbo