In the old days, CtrlAltDelete was used as a last measure with an unresponsive computer. If things were locked up, CtrlAltDelete would do a “soft” restart. It worked because the key combination was captured by the BIOS to run an interrupt routine in the operating system. Today, the “three finger salute” does a lot more than a restart. CtrlAltDelete is also used for everything from logging in to changing a password.
It’s loosely forwards-compatible with the old method. CtrlAltDelete now brings up a menu where the “Shutdown” button can be pressed, which then opens a dialog where you select the “Restart” function and click “OK”. Not so simple anymore! And not as effective on an unresponsive machine.
The additional functions are definitely not backwards-compatible, and it creates problems. I had a Linux box in the server room that was mysteriously rebooting, and everything I checked looked okay. I finally figured it out one day while watching the Windows administrator fumble with the KVM switch. He kept switching to the wrong machines and hitting CtrlAltDelete to get the screen to come on. Of course, this was causing the Linux machine to faithfully reboot! Fortunately, I was able to disable the CtrlAltDelete reboot in Linux.
Speaking of Linux, it doesn’t bother with the nonsense of extending CtrlAltDelete past its original intent. To login, I simply enter my login information. To change my password, I simply run the change password program. If an application locks up, the window manager will let me kill it. No need to overload a single key sequence to handle everything.
One more CtrlAltDelete annoyance to mention. I like keyboard shortcuts, so when I want to leave my Windows machine, I hit CtrlAltDelete and then Enter, which defaults to locking the screen. Sometimes the dialog doesn’t come up quickly enough and my Enter keystroke is lost. Unfortunately, I’m in a hurry when I do this, so I don’t notice the mistake. I come back to a monitor that has gone to sleep. Thinking I will be typing into the Locked Screen dialog, I hit CtrlAltDelete followed by my password and Enter. By sheer luck, my password contains the letter “s”, which is the quick key for “Shutdown”.
Let me leave you with a quote from David Bradley, who invented CtrlAltDelete while working for IBM: “I may have invented it, but Bill made it famous.” I doubt Bill saw any humor in that comment.