If you're Bill Gates, what regrets do you have? Apparently, CTRL+ALT+DEL is one of them.

The famous, three-finger combination of keys was intended to purposely slow people down, Gates said last week in an interview with David Rubenstein at the opening of a fundraising drive at Harvard University. The three-finger salute, as some call it, is used to force an application to quit or to reboot the machine. In the 1990s, it also became the way a user logged onto a Windows computer.

He said that when you turn your computer on, "you're going to see some screens and eventually type your password in, you want to have something to do with the keyboard that is signaling to a very low level of the software, actually hardcoded in the hardware, that is really bringing in the operating system you expect."

The IBM Guy

He said that Microsoft could have gone with a single button, "but the guy that wanted to do the IBM keyboard design didn't want to give us our single button and so we programmed at a low level," which he admits now was "a mistake."

It's a mistake that has persisted to this day, since it is still part of Windows 8.

The guy who actually created CTRL+ALT+DEL, a programmer named David Bradley, told Mental Floss magazine that he developed the keyboard shortcut in the spring of 1981 in order to perform a system reset without triggering memory tasks to assist him in programming and debugging IBM's new personal computer. He said that he chose the three keys because it seemed unlikely they would all be pressed accidentally at the same time.

The IBM Negotiations

Gates also told the audience that his involvement with Microsoft when he was in his 20s was "everything, every minute, every sense of I'm doing good work." He admits that it was "kind of extreme," as he knew everybody's license plate and could tell when they left work. From that intensity, he said, he went to "having a wife, having kids, having vacations," which felt "really good, really appropriate."

Rubenstein also asked Gates about one of the most famous and arguably the costliest business mistakes of all time -- IBM's decision to license the Microsoft operating system software instead of buying it outright.

Gates, in a classic understatement, said that Big Blue "certainly made a mistake." He pointed out that the IBM PC project was actually "started by the IBM management committee more to prove that they could do products quickly," than to actually create a best-selling product line.

He recalled, as others have pointed out, that IBM's sales projections for its new PCs were "200 (thousand) to 300 thousand units over three years, so they didn't view it as important." On the other hand, Microsoft thought it was going to be "super-high volume," and the difference in projections was reflected in "the way they negotiated with us," Gates said.