Keep having problems with the windows backup tool so went looking for an alternative.
Found this :
http://www.freefilesync.org/Seems to work quite well. You can sync two folders - so I just synced my user folder with all my stuff in to a backup drive. It can be automated too, but I chose to use a batch file that I run every now and then.
You can compare the two folders too, so you can see what's old/new if you need to.