won't you just be able to create user accounts in windows?
Also if you use bt they use a log on for their browser ( yahoo ) that only keeps the history of the current user.
I also use mcafee family protect that sets up passworded accounts that work with ( I believe ) any browser ... Turn it off for your frankie vaughn , log out of your secure browser and then allow the kids to log on.
It's free with bt packages about £25 to download from mcafee for a 3 pc license.