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.

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.

ReactOS has and will continue to incorporating features from newer versions and sometimes even define the state of the art in operating system technology.

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 0.3.1 is still in alpha stage, meaning it is not feature complete and is not recommended for everyday use.

Discussion forum:


You can run this project from Windows 98 and above. This project is not restricted by Windows Vista UAC (User Account Control)

An internet connection will be needed for the first time that this project is executed to allow downloading the needed binaries (around 8Mb)


Press the Play button (blue triangle)

No other configuration is needed, you can also modify or add your scripts as needed to change settings.


At the moment no bugs were reported, there is the limitation that this OS can only acess FAT32 partitions - no support for NTFS was yet added up to this point.

Change log

Please let us know if this page is not complete or in case you still haven't found the needed information.