No. "ClickOnce" does not use any special protocols to transfer files. So you can use a regular file share, IIS or any web server. If you are using a web server, there are a few additional considerations. First, you may need to configure the MIME type (application/x-ms-application) for the .application extension. Second, you may need to configure your server to unblock any restricted file extensions used by your app, such as .exe, .dll, .config., manifest, etc. Third, if you want to use HTTP compression, you will need IIS6 and HTTP 1.1.