Free open source Windows® XP /NT compatible operating system.
ReactOS® is an advanced free open source operating system providing a ground-up implementation of a Microsoft Windows® XP compatible operating system. ReactOS aims to achieve complete binary compatibility with both applications and device drivers meant for NT and XP operating systems, by using a similar architecture and providing a complete and equivalent public interface.Download
ReactOS is the most complete working model of a Windows® like operating system available. Consequently, working programmers will learn a great deal by studying ReactOS source code and even participating in ReactOS development.
In short, ReactOS is aiming to run your applications and use your hardware, a free operating system for everyone!
Please bear in mind that ReactOS is still in alpha stage, meaning it is not feature complete and is not recommended for everyday use.
NOTE: This download is in ISO format. You will need a program like NERO to burn it to an instalation CD.