If you are genuinely curious, try adding a little more time in the KillTaskManager loop. No fuss, no hoops to go through.

I'd be willing to withdraw questionable, or missusable submissions, but the codeguru seems to have no problem with it.

I am curious if this works on Vista, but I'd trust my own objective tests for that.

It may be easier to circumvent the code if you've gotten a chance to look at it up close. But what if you didn't?
I could circumvent it myself, in about five different ways back and forth.
I'm not sure if there is an end to it...
However there is no subjective guarantee either way, as you put it.
Did you make any changes to the code, or your system before trying it?
It looks a little like you have.

Until then I am just stating for the record that this doesn't work on my XP Pro machine, I am just saying it in case someone comes along and thinks they could copy/paste this code into their app and the end user won't be able to hit ctrl+alt+delete
For the record this code works on everyone elses PC except yours. You are the first person, of at least a dozen others.