Windows: Most Windows computers these days have a recovery partition built in, but it contains all the crapware that came with your computer. If you’d like to create your own recovery partition, AOMEI adds that backup function to any PC.
Programs like Steady-State protect a PC by letting you undo any recent changes, but this is different. It creates an image of your hard drive on another partition (you’ll need the space) or external hard drive. When your system gets hosed, you can return it to the last image from the Windows boot menu. Unlike Windows System Restore, this will overwrite any existing stuff you have on the drive. For nasty viruses that you can’t get rid of, this is another tool in your arsenal.