Sorry, I couldn't find pricing data for that day. The closing price for Microsoft (MSFT) on August 20, 2010 was $18.39. It was down 0.3% for the day. The latest price is $510.96.
DATE
OPEN
HIGH
LOW
CLOSE
VOLUME
August 20 2010
$18.45
$18.52
$18.37
$18.39
49,560,100
Daily pricing data for Microsoft dates back to 3/13/1986, and may be incomplete.