Exhibit 13.1 Quarterly Information (In millions, except per share data) (Unaudited) Quarter Ended - ------------------------------------------------------------------------------------------------------- Sept. 30 Dec. 31 Mar. 31 June 30 Year - ------------------------------------------------------------------------------------------------------- 1998 Revenue $ 3,334 $ 3,792 $ 3,984 $4,152 $15,262 Gross profit 2,800 3,179 3,344 3,479 12,802 Net income 663 1,133 1,337 1,357 4,490 Basic earnings per share 0.14 0.24 0.27 0.27 0.92 Diluted earnings per share 0.13 0.21 0.25 0.25 0.84 Common stock price per share: High 37.69 36.66 45.47 54.28 54.28 Low 30.82 29.50 31.10 40.94 29.50 - ------------------------------------------------------------------------------------------------------- 1999 Revenue $ 4,193 $ 5,195 $ 4,595 $5,764 $19,747 Gross profit 3,544 4,407 3,887 5,095 16,933 Net income 1,683 1,983 1,917 2,202 7,785 Basic earnings per share 0.34 0.40 0.38 0.43 1.54 Diluted earnings per share 0.31 0.36 0.35 0.40 1.42 Common stock price per share: High 59.81 72.00 94.63 95.63 95.63 Low 47.25 43.88 68.00 75.50 43.88 - ------------------------------------------------------------------------------------------------------- 2000 Revenue $ 5,384 $ 6,112 $ 5,656 $5,804 $22,956 Gross profit 4,672 5,356 4,904 5,022 19,954 Net income 2,191 2,436 2,385 2,409 9,421 Basic earnings per share 0.43 0.47 0.46 0.46 1.81 Diluted earnings per share 0.40 0.44 0.43 0.44 1.70 Common stock price per share: High 100.75 119.94 118.63 96.50 119.94 Low 81.63 84.38 88.13 60.38 60.38 ======================================================================================================= The Company's common stock is traded on The Nasdaq Stock Market under the symbol MSFT. On July 31, 2000, there were 107,824 registered holders of record of the Company's common stock. The Company has not paid cash dividends on its common stock.