I bought a Pluscom USB adapter from thepihut.com which worked straight out of the box.
After wasting hours if not days with an Asus N10 I was relieved to find a wireless adapter that worked and ordered another from the same source. What I received was a different model which has so far evaded all my efforts to get it recognised and working - either with the Pi or with Windows. This may be a one off problem on which I am awaiting a reply from thepihut. They seem excellent people and I am sure they will resolve the issue.
Meanwhile, I would love to know where to get hold of more Pluscom adapters.