I too recently had the problem of my main computer not even starting windows. The very useful restore points on my xp system were useless as I could not start windows to get to them.
However, I back up all my data daily and had copies on cd and another computer, so all I had to do was reinstall windows and copy back my data.
It is sad to say that people only learn to backup their data regularly once they have lost some. Most computer owners who do not back up their data will say it takes too much time. I would reply that it takes even longer to re-enter the data and that often this is not possible as there are no hard copies of the data.
Regular backups of data can usually be automated so that all the user has to do is press a button or click on an icon. Yes they will have to wait while their data is backed up, but unless they are generating loads of data every day it should not take long. Only the data needs to be backed up regularly as you can always reinstall the programs from the original disks if that is necessary.