We are experiencing a problem in uploading files to web server using the WEBCLIENT interface in Windopws 2008. Our application code was working perfectly when our IIS server was running in Windows 2003 but when we ported it to Windows 2008, it started throwing "(404) Not Found" exception. This happens on  the "GetResponse()" method of webrequest. An excerpt from code is given below.

// The WebRequest

oWebrequest = (HttpWebRequest)WebRequest.Create(oUploadURL);

oWebrequest.ContentType = "multipart/form-data; boundary=" + sBoundary;

oWebrequest.Method = "PUT";

// This is important, otherwise the whole file will be read to memory anyway...

oWebrequest.AllowWriteStreamBuffering = false;

// Get a FileStream and set the final properties of the WebRequest

oFileStream = File.OpenRead(vsLocalPath);

iLength = oFileStream.Length;

oWebrequest.ContentLength = iLength;

oWebrequest.KeepAlive = false;

oWebrequest.Timeout = 4 * 60 * 60 * 1000; //4 hours; //20 * 60 * 1000

oRequestStream = oWebrequest.GetRequestStream();

// Stream the file contents in small pieces (4096 bytes, max). [changed to 65536, 262144]

bFile = new Byte[iChunkSize];

//Upload the file

while ((iBytesRead = oFileStream.Read(bFile, 0, bFile.Length)) != 0)

{

               oRequestStream.Write(bFile, 0, iBytesRead);

       iProcessedSoFar += iBytesRead;

}

//Get response of transfer

oWResponse = oWebrequest.GetResponse();

oResponseStream = oWResponse.GetResponseStream();

oResponseReader = new StreamReader(oResponseStream);

rsErr = oResponseReader.ReadToEnd();