"If you have lost, broken, or misplaced your original installation CD, you can order replacement media from Microsoft.
MORE INFORMATION
Order a Replacement CD
U.S. customers can contact the Microsoft Order Desk at the following phone number:
(800) 360-7561, Monday through Friday, 5:00 A.M. to 7:00 P.M. Pacific time.
Canadian customers can contact the Canadian Order Desk at the following number:
(800) 933-4750, Monday through Friday, 5:00 A.M. to 7:00 P.M. Pacific time. "

microsoft.com