Register and go to the production releases downloads.
It's a tiny little 50 meg download. This is a complete install, not an update, so remove your old Houdini install before installing this one. It's available for Win32, Linux 6 and 7, Irix, and Solaris. The license manager will try to install keys at the end of the installation. Just close it and start Houdini Master and it will allow you to install a non-commercial license. Have fun.