CEO and president Hewlett-Packard 2010 rank: Return Age: 55
Sheís back! In late September the losing California gubernatorial candidate -- and former No. 1 MPW -- was named CEO of HP, Americaís largest tech company by revenue. While
her ascent to the role is a sure sign of her power, it remains to be seen if she can fix the computer maker and bring order to its dysfunctional board.
The list is compiled by FORTUNE editors, who consider four criteria: the size and importance of the womanís business in the global economy, the health and direction of the
business, the arc of the womanís career (resume and runway ahead), and societal and cultural influence.