I don't think you were asking for a very ethical solution. Yes, constant physical access to the computer is probably the best way, and more trusting. But then this son will most likely find other sources of internet, if he is indeed doing something other than Myspace, Facebook.
I do not know if spying on these teens is the best option you have, it is just short of installing a webcam in their room. But Software and programming is available for this course of action.
In your post you mentioned you really did not want to download anything, since they all have some sort of malware involved. They must have malware in it, or the program would run like any other. This computer savvy teen you have would easily find it in the task bar, task manager, or whatever else. If curiousity overcomes dread, then read this:http://ezinearticles...-...&id=1433252
It's not a spouse, but same idea. He may already have anti-keylogging software on the computer, so even if you downloaded a keylogger, it could also not work. If you found something that
Unfortunately, there is no plausible solution. You could start learning C++ or other languages, by the time they are out of High School you will start to learn how to program this sort of thing. But it's very extensive, and I couldn't find that sort of code anywhere online.
So one viable option is to find source code for a keylogger. Try searching google.com or bing.com for something like "C++ keylogger source code" and snoop around. You would also need a compiler for the language. I'm afraid nothing like this can be done in a native language (i.e. Windows batch).
Your second option is to get Software that saves history elsewhere (keyloggers are way too dangerous for my taste). So these links are safer, but not guaranteed:Internet ExplorerFirefox(not sure, but try it)
Edited by Mrco, 22 August 2009 - 10:39 PM.