If you backup an exact image and some virus/other issue occurs you can restore your system to just like it was before the issue.
In some cases folk decide it's not worth backing up. Again, all our choice on the matter.
With the advent of the end of support by Microsoft for their Win XP os, how will this effect the normal home user of XP? I am updating everything thing that I can think of prior to the end, but, is there any thing else the average user can do?