In the past, when Windows asked if I'd like it to remember my passwords and user names I have said yes. Now I'd like to remove that info so passwords and user names must be entered each time. How and where do I do this? I have Norton System Works 06 installed if that helps.

I'm assuming you are using Internet Explorer:
Go to Tools in the top menu bar then select Internet Options; select the Content tab, click on AutoComplete button, uncheck "User names and Passwords on forms"

Thanks very much! Now I won't be saving any new ones, but how do I get rid of the ones I've already saved?

In that same box, a little lower, there is a Clear Passwords button.

Great! Problem solved! Thanks for the help!