He said that something had to be done with the keyboard that was signaling to a very low level of software, to bring in the operating system one expects, instead of a funny piece of software that looks like a log in screen, and then listens to the password, adding that it was a mistake.
David Bradley, a designer of the original IBM PC, invented the 'Control-Alt-Delete' combo, the report said.
Bradley said that he may have invented it but it was Gates who made it famous.
He himself admitted that he did not know why they used the same command for log in, which was used to restart the computer, the report added.
Video: Bill Gates admits control-alt-delete was a mistake, blames IBM