īradley is also known for his good-natured jab at Gates at the celebration of the 20th anniversary of the IBM PC on Augat The Tech Museum: he quickly added it was a reference to Windows NT logon procedures ('Press Ctrl + Alt + Delete to log on'). īradley viewed this work as just one small task out of many: 'It was five minutes, 10 minutes of activity, and then I moved on to the next of the 100 things that needed to get done.' In a March 2018 email, one of Bradley's co-workers confirmed the command was invented in 1981 in Boca Raton, Florida. The feature, however, was detailed in IBM's technical reference documentation to the original PC and thereby revealed to the general public. Bill Gates (former Microsoft CEO) remembered it as 'just something we were using in development and it wouldn't be available elsewhere'.

The feature was originally conceived only as a development feature for internal use and not intended to be used by end users, as it triggered the reboot without warning or further confirmation-it was meant to be used by people writing programs or documentation so that they could reboot their computers without powering them down. According to his own account, Mel Hallerman, who was the chief programmer of the project, therefore suggested switching the key combination to Ctrl+ Alt+ Del as a safety measure, a combination impossible to press with just one hand on the original IBM PC keyboard. Bradley, as the chief engineer of the IBM PC project and developer of the machine's ROM-BIOS, had originally usedĬtrl+ Alt+ Esc, but found it was too easy to bump the left side of the keyboard and reboot the computer accidentally.

The soft reboot function via keyboard was originally designed by David Bradley. Original IBM PC 5150 keyboard: It is impossible to press Ctrl+Alt+Del with one hand only

Control alt delete without keyboard