If your Operating System is Windows XP, 2000, NT, MCE, etc. (XP 64-bit not supported; not tested with Windows 98/ME) . . . . I would try this little program called >>> NAOMI <<<
It isn't a Website filter, but an advanced internet content filtering program, easy to use and totally free, intended for families, and kids in particular.
The program is protected by password which you are prompted for during installation. I have installed it on a few Systems and it's very impressive.