I've got an upload page that takes in a file, then posts it out to a remote server that listens (using an HttpHandler) for requests, pulls in the file, and saves locally. This all works great, actually, EXCEPT, when the file that is being posted out to the remote server is > 3 MB. Is there a size limitation to using the WebClient.UploadValues() function? I get a: The remote server returned an error: (400) Bad Request. Error. I think this has something to do with the framework, because it only occurs with larger sized files. But it could possibly be IIS blocking the POST requests because of the size? Anybody have any ideas about this problem, or possibly a work around?