It's simpler than that... Just download any dictionary (I recommend Tagaini Jisho -
http://tagaini.net) and enable the Tablet PC Input Panel (TIP) in Vista. Then you'll be able to click on the input text field in the dictionary and a handwriting recognition panel will pop-up.
I'm using it both on my Tablet PC (Dell Latitude XT) and on my PC with a Wacom Tablet