Protecting kids from Kazaa

In the comments to an earlier post, Ken asks:

Is there a way, e.g., a setting from within Internet Explorer, or perhaps his antivirus program (Norton, I think), to prevent his teenage daugher (the real culprit here) from downloading this especially malicious crudware in the first place?   

Sure there is, and I’ve done it for neighbors. This assumes, of course, that they’re using Windows XP and that they are willing to enforce some serious rules. Set the daughter up with a Limited user account (LUA). Give Mom or Dad the password to the Administrator account and tell them not to share it with the kid no matter what. A user who logs on with an LUA cannot install a software program that tries to write any files outside of their own user account. They can’t make changes to global security settings, and they can’t install add-ons for Internet Explorer. In other words, they can’t be tricked into installing adware, spyware, or viruses.

The kids will scream when they can’t do what all the other kewl kids are doing, but that’s just too bad. When I set this up at my friend’s house, the deal was that if her son wanted to install any program, he first had to research it and prove that it was safe, reliable, and trustworthy. Needless to say, Kazaa never made it back onto the machine, and I’ve never had to go back and clean up a single piece of spyware. Oh, and he just made the Dean’s list.