Thanks for the pointers people, this is the solution I finalised on.
Code:
 string SaveTo;
            var assembly = System.Reflection.Assembly.GetExecutingAssembly();
            var stream = assembly.GetManifestResourceStream("CRSUsageReport.Resources.busy.gif");
            var tempPath = Path.GetTempPath();
            int Length = 256;
            Byte[] buffer = new Byte[Length];
            int bytesRead = stream.Read(buffer, 0, Length);
            // write the required bytes
            SaveTo = tempPath + "busy.gif";
            FileStream writeStream = new FileStream(SaveTo, FileMode.Create, FileAccess.Write);

            while (bytesRead > 0)
            {
                writeStream.Write(buffer, 0, bytesRead);
                bytesRead = stream.Read(buffer, 0, Length);
            }
           stream.Close();
            writeStream.Close();

            this.webBrowser1.Navigate(SaveTo);