Even though I never tried, I doubt that it can be done. What I know for sure, you cannot disable Ctrl + Alt + Delete, for a good reason (otherwise it would be possible to block the system), and I don't think you can do what you want.
But you should not try to do such thing, as it would be a greatest abuse. Think about your users.
You should always explain your ultimate goals when asking question. So, I don't know what are you trying to achieve and why, but I have one guess. Maybe what you need is so called "kiosk mode". Please take a look:
Running a Web Site in Kiosk Mode with C#
c# program ctrl-alt-del screen windows 7