Why does Windows require CTRL+ALT+DEL to Logon?

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Has Microsoft ever offered an explanation for why they require CTRL+ALT+DEL to login? (Yes I know you can disable it, but it is still their preferred method.) It seems like at one point I heard that it was for security since you knew nothing else could trap CTRL+ALT+DEL, but I've written programs that trap CTRL+ALT+DEL, and it isn't that difficult, so I am pretty sure that was just a myth, either that or the decision to require CTRL+ALT+DEL is based on a fallacy.

Either way, I am curious if there is an official reason, and if that reason has any actual merit.

Thanks!

Jim McKeeth

Posted 2009-10-28T02:01:46.030

Reputation: 4 907

This question was re-asked as What makes Secure Login (CTRL+ALT+DEL) Secure?, where it got pretty much the same answer.

– G-Man Says 'Reinstate Monica' – 2015-04-30T21:27:38.430

This is a well known key sequence by every Windows users – Kami – 2009-11-19T09:39:41.493

2How can you trap the ctrl+alt+del key? Even remote desktop or virtual machine softwares cannot do that and must implement an alternative for this – phuclv – 2013-10-22T09:19:24.460

2Before that, it was a well known key sequence for every MS-DOS user – Kevin Panko – 2009-12-17T00:28:24.937

Answers

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This is the same as this Server Fault question: How does CTRL-ALT-DEL to log in make Windows more secure?.

Here is the accepted answer from there, by Oskar Duveborn:

The Windows (NT) kernel is designed to reserve the notification of this key combination to a single process: Winlogon. So, as long as the Windows installation itself is working as it should - no third party application can respond to this key combination (if it could, it could present a fake logon window and keylog your password ;)

Stephen Jennings

Posted 2009-10-28T02:01:46.030

Reputation: 21 788

Asked: 2009-10-28T02:01:46.030

Viewed: 4 622 times

Active: 2013-10-18T07:41:47.940