You can deploy the Windows application as an online-only app, and have the web project invoke a link to the application file. If you deploy it as online-only, you can pass information with query parameters (depending on how much info we're talking about).
How to retrieve query string information
http://msdn.microsoft.com/en-us/library/ms172242(VS.80).aspxIf you're talking about more info that you can pass in a query string, then you should write a web service and have the windows application call it to get the informatino it needs.
RobinS.
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