I am not sure, if your reply was to my post or not, anyway, here is what I did I opened up a new Windows Application (it doesn't matter what kind of project I open, I get the same error), then tried to follow the steps outlined by James, i.e. to add the Bing service reference. I obtained the AppID for my application and used that in the URL: http://api.bing.net/search.wsdl?AppID=027377727E0CB50903ACE9F02013887591002C3A&Version=2.2 and clicked Go. It seems to search for the site, then I do get the method available on the left side (but disabled) and on the right side of the window, I see this error - Operation is not valid due to the current state of the object. Due to this obviously the Add Reference button doesn't get enabled. So I am stuck at this point itself, forget about the actual testing of the Lookup method from James's article.