Gartner has released its quarterly PC sales survey for the fourth quarter of 2018, and it was the same old story. PC sales plunged in the fourth quarter and were down 1.3 percent for the year. The three top players — HP, Dell and Lenovo — accounted for 63 percent of sales worldwide in the quarter. The company found in their preliminary sales research that worldwide sales totaled 68.6 million units in the fourth quarter. That may sound like a big number, but it’s down 4.