How can I set my computer to require a code to access the internet?

When I am away from my office someone uses my computer to visit unwanted sites. If I could simply have a code to type in before being allowed to access the internet my problems would be solved. I do not understand how to set this up in my system.

How can I set my computer to require a code to access the internet?
HI,





1. Put a password for ur PC.





2. Turn on content advisor in internet explorer%26amp; put a password. (so if somebody opens explorer it will ask for the password)





this link give u the details





http://www.microsoft.com/windows/ie/ie6/...








Gud Luck
Reply:Is this wireless or LAN? If it's wireless you can just set a WEP key in your router's security configuration and unstore the key in your PC so it ha to be entered to go online; OR if it's a LAN, just password the computer; otherwise I'd look around download.com for an internet connection lock, or restriction, or any other term that fits what you're looking for.