The One Laptop per Child project will now load Windows onto its cheap XO machines, as an alternative to Linux.
The aim of the non-profit project is deliver £50 laptops to poor countries.
Trials of Windows machines in key emerging markets will begin as early as next month.
The intention is to create a version of the XO laptop that provides the ability to host both Windows and Linux operating systems, giving users the ability to run either.
"From the beginning, the goal of OLPC has been to use technology to transform education by bringing connectivity and constructionist learning to the poorest children throughout the world," said Nicholas Negroponte, founder and chairman of OLPC.
"Today's announcement, coupled with future plans for a dual boot version of the XO laptop, enhances our ability to deliver on this vision. In addition, OLPC will work with third parties to port its user interface, called Sugar, to Windows."
Craig Mundie, chief research and strategy officer at Microsoft, said, "By supporting a wide variety of affordable computing solutions for education that includes OLPC's XO laptop, we aim to make technology more relevant, accessible and affordable for students everywhere."