ReactOS is open source. but it is NOT Linux, therefore it has none of the complexities of "most" linux/unix systems. Installation is very straightforward. If you can install windows 2000/XP then definitely you can also install ReactOS. Above all, it is "binary compatible" with windows 2000/XP, meaning you can windows applications and drivers.
Though I would like to remind everyone that ReactOS is still on alpha stage. Nevertheless feel free to try it for yourself. Go get it here, it is just 32.5MB for the zipped ISO.
http://www.reactos.org
Here are the screenshots of the ReactOS VM: