My name is Alexander Rechitksiy and I am representative of ReactOS Project (web-site http://reactos.org)
I ask you, “Imagine running your favorite Windows applications and drivers in an open-source environment you can trust. That’s ReactOS. Not just an Open but also a Free operating system.”
Despite what you may be thinking, ReactOS is not a Linux distro made to look and behave like Windows, however. It has actually been built from the ground up to be binary compatible with application and device drivers made for Windows XP\2003 and newer. ReactOS is streamlined and doesn’t require a powerful system and it is compatible with an array of popular Windows applications. There’s even a LiveCD download available if you’d like to give it a shot without committing to a full installation.
I want also inform you that, the first release candidate to the upcoming ReactOS 0.4.2 release is now available
There's a lot of improved file-system support that's been worked on for ReactOS 0.4.2, including read support for ReiserFS and UFS/FFS along with read/write support for EXT3 and Btrfs. ReactOS 0.4.2 also supports Cygwin and .NET 2.0/4.0
If you are interested in helping test this near final version of ReactOS 0.4.2, visit SourceForge.net for downloads
https://sourceforge.net/projects/reactos/files/ReactOS/0.4.2/
NOTICE: Please keep in mind that ReactOS project is still in alpha stage,
so do NOT install it on your main PC without proper backup!
But you can always try LiveCD or install it on virtual machine without any risk.