My user account has a password, but somehow even when I log it off, he is able to log back on and change things. "Norton AntiSpam" even allows him to turn things off without being logged in, and I don't know how to prevent this. All he has to do is right click Norton and click disable... is there a way I can lock it down??

Sounds as if his account has administrative rights.

If so then it may help to make his account limited or restricted.

Start > Run > type in box control userpasswords2 then push enter.

Highlight name > click properties button > click on Group Membership tab > change to restricted or whatever else you want to other then administrator.

Another thing you could do is NOT have the icon in the system notify tray. Go into Norton Internet Security options and there is a box you can uncheck so the icon is not there.