来自Windows服务的安全连接错误

我有一个windows服务，它将数据发送到一个安全的网页。这目前在visualstudio2010中运行的控制台应用程序中运行良好。我已经能够使用这种方法连接和发送数据。

问题出现在我部署和运行windows服务时，我现在收到以下错误"请求已中止：无法创建SSL/TLS安全通道。"

这是我用来将http发布到网页的代码

ServicePointManager.Expect100Continue = true;
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls | SecurityProtocolType.Ssl3;
ServicePointManager.ServerCertificateValidationCallback +=
            (sender, cert, chain, sslPolicyErrors) => true;
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
        request.ContentType = "text/xml; encoding='utf-8'";
        request.Method = "POST";
        doc.Save(request.GetRequestStream());
        X509Store store = new X509Store(StoreName.Root, StoreLocation.CurrentUser);
        store.Open(OpenFlags.ReadOnly);
        var certif = store.Certificates.Find(X509FindType.FindByThumbprint, "‎539B640BD981BFC48A366B8981B66F301C8A3959", false);
        request.ClientCertificates.Add(certif);
        try
        {
            using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
        {
            if (response.StatusCode == HttpStatusCode.OK)
            {
                success = true;
            }
        }
        }
        catch (Exception ex)
        {
            error = ex.Message + " " + ex.InnerException;
        }

我已经检查了证书存储，正确的证书在windows服务的受信任根目录中。TLS/SSL连接的另一个方面与窗口服务不同吗？人们有任何想法都将不胜感激。