I'm on win xp. What about yours?
Do you have 12 sample stencyl games (6 0f them ios)?
You should preferably save your behavior to somewhere below document folder and then drag it directly into SW from windows filesystem.
I used a behavior called Alien Movement in a game called Alien Approach. Look for that, export it to a document folder and you should see a spaceship, then open another game, go to behavior list, you may see a bunch of folder, just drag the spaceship icon over next to all these folders.