If you have Windows XP: why not make a separate account for your kids, a regular user, not administrator ofcourse. You have your account or even a special bot account (also regular user ofcourse, even you should be normal user most of the time ideally) and the kids have theirs, and fast user switching makes everyone have his own stuff that others can't access without knowing the password. The task manager won't allow them to kill your processes, it will allow them to hit the off button tho
