If you pressed Control-Alt-Delete to log on before reading this, Bill Gates says he's sorry. The Microsoft founder says the triple-key login should have been made easier, à la Apple's Macs, but that a designer insisted on the more complicated step. "We could have had a single button. But the guy who did the IBM keyboard design didn't want to give us our single button," Gates said Saturday during a question-and-answer session to launch a Harvard University fund-raising campaign. His comments have gained attention since a video of his Harvard Q&A was posted on YouTube on Tuesday....