Uri url = new Uri(@"http://www.mysite.com/MyFolderTemp/UpdateProg.xml");
using (System.IO.Stream streamRemote = this.MyWebClient.OpenRead(url))
{
	using (System.IO.Stream streamLocal = new System.IO.FileStream(@"C:\Temp\UpdateProg.xml", System.IO.FileMode.Create, System.IO.FileAccess.Write, System.IO.FileShare.None))
	{
		int iByteSize = 0;

		byte[] byteBuffer = new byte[iSize];

		while ((iByteSize = streamRemote.Read(byteBuffer, 0, byteBuffer.Length)) > 0)
		{
			streamLocal.Write(byteBuffer, 0, iByteSize);
		}
		streamLocal.Close();
	}
	streamRemote.Close();
}

System.Net.WebClient MyWebClient = new System.Net.WebClient();

System.Net.Cache.RequestCachePolicy TempNoCachePolicy = new System.Net.Cache.RequestCachePolicy(System.Net.Cache.RequestCacheLevel.NoCacheNoStore);

this.MyWebClient.CachePolicy = this.MyNoCachePolicy;