On windows solitaire standard scoring whats the highest possible score

Max PointsYou get five points for moving a card to the stacks on the bottom (including turning a card over) and 10 points for moving a card to the ace stacks. So that's 52 x 5 + 52 x 10 = 780. The bonus is calculated using the formula 700 000 / number of seconds. The number of seconds has to be over 30 or no bonus is awarded. Therefore 700 000 / 30 + 780 = 24113. This is the highest possible score you can achieve.

Source: http://support.Microsoft.com/kb/101766

correction: when you start out, there are 7 cards already turned, so you cannot get the 5 points for turning them, so the 780 must be reduced by 35, for a max of 745.