TheSpreader

As I stated the other day, my son is getting all this crap in his head and just out of curiousity I went through the history and didn't like what I found. I don't want him using the computer without me around and somehow he knows how to bypass my login password. He's smart for a 9 year old!

Is there something I can purchase that will lock the computer? I did a Google search but the only thing I can find are the locking devices that protect from theft and not what I'm looking for. Any advice will be appreciated.

Thanks!