I am not sure how this appeared one day on my computer, but for me was very annoying. In the right circumstances this feature would be very useful. Removing it was a little hidden from the usual.
To remove in Vista, go to “Uninstall a program”, select “Windows Live Essentials” and click Uninstall/Change. You will need administrative rights to continue. Make sure Uninstall is selected in the Window Live window and continue. Select Family Safety in the next window and continue.
Doing this removes the Windows Live Family Safety Client from your local machine. If you have enabled Family Safety, remember to log into you Live Account and go to Family Safety Summary (https://fss.live.com/safety/default.aspx). Remove the account and computers that may have been created.
Good Luck! Peter