Disable Ctrl+Alt+Del Combination on windows7

Question

I'm working on an app (Written in C#) that have a setting to run on KIOSK mode. I've just an challenge here which is disabling Ctrl+Alt+Del combination Event.

There is no right answer in the similar past posts. Please let me know about the right action. Considering, my code is working with registry keys to disable/enable options, if you know any registry key,it will be more helpful.

Answer 1

CTRL+ALT+DEL is the secure attention sequence of Windows NT (and its derivatives like Win7). It is the one key combination that is guaranteed to get the OS's attention. The whole point of the SAS is that it can't be intercepted or stopped by user programs.

One security issue it addresses is that of a false login screen: consider a screen that looks exactly like the normal Windows login screen. There's no way to tell that it's a fake just by looking at it. But, if you're in the habit of always pressing CTRL+ALT+DEL before logging in (there is an option to always require it for the legitimate screen), pressing the SAS on a false login screen will bring up task manager or the secure attention screen (with the log off, change password, etc options). The real login screen doesn't do that; it just stays there on the screen. As long as the OS itself isn't replaced or compromised, CTRL+ALT+DEL will protect you from false login screens. If a user program could intercept the SAS, it wouldn't be worth anything.

The SAS was baked into the Windows NT design right from the beginning (it was in the first release in 1993), so getting around it won't be easy. I'm sure there are keyboard filter drivers-- or something to intercept that sequence-- that are designed for kiosk use.

Answer 2

It is not possible to capture CTRL+ALT+DEL, it is so by design in all Windows systems. This is a security issue, if the user hits CTRL+ALT+DEL, he or she should be certain that it is the operating system and not some application (possibly a password-catching trojan) that responds to it.

I guess to capture CTRL+ALT+DEL you would need to write a device driver of some sorts.

Edit: Also see This answer. I did not try it, but the question is fairly similar.