不同用户的webRequest不起作用

当我用我的用户在我的工作站上运行它时,一切都很好,但如果我在我的工作站上以不同的用户身份运行它(用于在exe文件上更改用户shift+鼠标右键):

using (Stream requestStream = restRequest.GetRequestStream())

引发异常

无法建立连接,因为目标计算机处于活动状态

但是,当我将应用程序复制到另一个用户站并尝试运行它时,它工作正常,对我的用户来说也完全一样

可能是什么?

我的简单代码:

JavaScriptSerializer jsonSerializer = new JavaScriptSerializer();
Dictionary<string, object> deserializedJsonDictionary;

HttpWebRequest restRequest;
WebResponse restResponse;

try
{
    string connectionParams = "{some json params for api...}";
    restRequest = (HttpWebRequest)WebRequest.Create(URI);
    restRequest.Method = Method; //post
    restRequest.ContentType = ContentType; // application/json

    using (Stream requestStream = restRequest.GetRequestStream())
    {
        byte[] inputStringBytes = Encoding.UTF8.GetBytes(connectionParams);
        requestStream.Write(inputStringBytes, 0, inputStringBytes.Length);
    }

    using (restResponse = restRequest.GetResponse())
    {
        using (Stream responseStream = restResponse.GetResponseStream())
        {
            StreamReader rdr = new StreamReader(responseStream, Encoding.UTF8);
            string Json = rdr.ReadToEnd();

            deserializedJsonDictionary = (Dictionary<string, object>)jsonSerializer.DeserializeObject(Json);
        }
    }
}
catch(Exception ex)
{
    throw ex;
}