It's a separate and independent program. It's attached here. If you are a licensed v2006 (or later) DirectRT user, go ahead and download and install the package. Send us the number that comes up when you try to run it (via sales@empirisoft.com) and we'll send you an authorization code. Just let us know what account you're using.
Note that the documentation (readme.pdf) and license are posted separately in case you want to check them out first.
We have NOT tested InputRT on Vista.
-Blair