Download official riecoin wallet from here:
http://www.riecoin.org/download.html
or from here:
http://download.riecoin-community.com/r ... .2-win.zip
Extract the archive and run 32bit or 64bit version (depending on your windows version if is 32bit or 64bit )
Start the installer
Select where to install (usuali C:\Program Files\Riecoin)
Select where to create data dir (you will need a lot space in that location)
After installation is over, run your riecoin wallet. If you have problem with syncing to the network (it not starting) download this:
http://download.riecoin-community.com/riecoin.conf
and put it in your data dir (second directory what you choose in installation)
enjoy.