KDE on Windows has the aim to port KDE applications to Microsoft Windows. Our general rationale is that KDE is awesome, Linux is awesome, but Windows still dominates the world for a multitude of reasons. So if you are forced to use Windows at least you will have the alternative of Free KDE Applications in the propietary Windows world. In that we are making KDE available for millions and millions of people. (Probably including your parents and grandparents ;) )
The KDE on Windows Initiative is an ongoing project to port the KDE applications to MS Windows.
For more information about us see: http://windows.kde.org/people.php
If you want to join us the best place is our IRC channel:
kde-windows on freenode
and join our mailing list!
All this and more on: http://windows.kde.org/
The preferred method for installing most KDE applications under Windows is the KDE-Installer. However, the most recent version available from the installer is KDE 4.10.2. Many KDE applications have since been ported to the more modern "KDE Frameworks / KF5" libraries, and some have started providing Windows installers. Due to the more modular nature of KDE Frameworks, there is no single installer for these applications. Rather, please refer to the website of the application(s) you wish to install or check the instructions on building KDE on Windows from source.