You're good to not rely on System Restore, as its data resides in an area of the computer that can easily be attacked, corrupted, compromised, etc.
A while back I learned about a program called Rollback Rx. I since disabled WSR and strictly started using Rollback. Honestly it's much better than WSR, and in my tests could recover from many things that WSR simply couldn't.
You could disable it and just back up and re-image but that can be a lengthy process, my recommendation is that you find a substitute for WSR and use a layered defence. I mentioned Rollback, but there are alternatives out there like Comodo Time Machine and Shadow Defender. So you may want to consider this before you stick strictly with disk imaging.