The steps to be followed in short:
Download the installer here
Then follow the installation procedure like for any other Windows software - screenshots are here.
When you come to the Package selection screen, select the language(s) you wish the software to be available in and the package - in this case kdeedu. If you don't select any language you will automatically get English.
Then finish the installation process by clicking on next, following the coming screens just like you normally do with other windows software.
Please note that the Parley team does not deal with the Windows-Installer and therefore we cannot easily answer your questions. Should you have difficulties, please contact the KDE-Windows team directly. You can do so by subscribing to the mailing list here or join them on IRC at irc://freenode.net Channel: #kde-windows.