Upload Large File In MVC Encountered an Error

I have a .txt file that the size up to 2GB, i want to upload that file from client to a folder in a server, while uploading that file, there is an error, this is what the page says:

An operation was attempted on a nonexistent network connection. (Exception from HRESULT: 0x800704CD) 
  Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

 Exception Details: System.Runtime.InteropServices.COMException: An operation was attempted on a nonexistent network connection. (Exception from HRESULT: 0x800704CD)

Source Error: 


 An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.  

Stack Trace: 



[COMException (0x800704cd): An operation was attempted on a nonexistent network connection. (Exception from HRESULT: 0x800704CD)]

[HttpException (0x80004005): An error occurred while communicating with the remote host. The error code is 0x800704CD.]
   System.Web.Hosting.IIS7WorkerRequest.RaiseCommunicationError(Int32 result, Boolean throwOnDisconnect) +3399867
   System.Web.Hosting.IIS7WorkerRequest.ReadEntityCoreSync(Byte[] buffer, Int32 offset, Int32 size) +9621484
   System.Web.Hosting.IIS7WorkerRequest.ReadEntityBody(Byte[] buffer, Int32 size) +24
   System.Web.HttpRequest.GetEntireRawContent() +315
   System.Web.HttpRequest.GetMultipartContent() +63
   System.Web.HttpRequest.FillInFormCollection() +160
   System.Web.HttpRequest.EnsureForm() +69
   System.Web.HttpRequest.get_Form() +13
   System.Web.HttpRequestWrapper.get_Form() +14
   System.Web.Mvc.HttpRequestExtensions.GetHttpMethodOverride(HttpRequestBase request) +121
   System.Web.Mvc.AcceptVerbsAttribute.IsValidForRequest(ControllerContext controllerContext, MethodInfo methodInfo) +37
   System.Web.Mvc.HttpGetAttribute.IsValidForRequest(ControllerContext controllerContext, MethodInfo methodInfo) +39
   System.Web.Mvc.ActionMethodSelectorBase.IsValidMethodSelector(ReadOnlyCollection`1 attributes, ControllerContext controllerContext, MethodInfo method) +54
   System.Web.Mvc.ActionMethodSelectorBase.RunSelectionFilters(ControllerContext controllerContext, List`1 methodInfos) +132
   System.Web.Mvc.ActionMethodSelectorBase.FindActionMethods(ControllerContext controllerContext, String actionName) +142
   System.Web.Mvc.ActionMethodSelectorBase.FindActionMethod(ControllerContext controllerContext, String actionName) +104
   System.Web.Mvc.Async.ReflectedAsyncControllerDescriptor.FindAction(ControllerContext controllerContext, String actionName) +54
   System.Web.Mvc.ControllerActionInvoker.FindAction(ControllerContext controllerContext, ControllerDescriptor controllerDescriptor, String actionName) +16
   System.Web.Mvc.Async.AsyncControllerActionInvoker.BeginInvokeAction(ControllerContext controllerContext, String actionName, AsyncCallback callback, Object state) +114
   System.Web.Mvc.Controller.<BeginExecuteCore>b__1c(AsyncCallback asyncCallback, Object asyncState, ExecuteCoreState innerState) +25
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallBeginDelegate(AsyncCallback callback, Object callbackState) +30
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +128
   System.Web.Mvc.Controller.BeginExecuteCore(AsyncCallback callback, Object state) +468
   System.Web.Mvc.Controller.<BeginExecute>b__14(AsyncCallback asyncCallback, Object callbackState, Controller controller) +18
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallBeginDelegate(AsyncCallback callback, Object callbackState) +20
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +128
   System.Web.Mvc.Controller.BeginExecute(RequestContext requestContext, AsyncCallback callback, Object state) +374
   System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.BeginExecute(RequestContext requestContext, AsyncCallback callback, Object state) +16
   System.Web.Mvc.MvcHandler.<BeginProcessRequest>b__3(AsyncCallback asyncCallback, Object asyncState, ProcessRequestState innerState) +52
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallBeginDelegate(AsyncCallback callback, Object callbackState) +30
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +128
   System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContextBase httpContext, AsyncCallback callback, Object state) +384
   System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContext httpContext, AsyncCallback callback, Object state) +48
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.BeginProcessRequest(HttpContext context, AsyncCallback cb, Object extraData) +16
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +103
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155

And this is some of the code:

    public ActionResult UploadFile_Post(FormCollection dt, string btn, HttpPostedFileBase uploadFile, FileUpload dataFile)
    {
      string nameFile, getExtension = "";
      nameFile = System.IO.Path.GetFileNameWithoutExtension(uploadFile.FileName.ToString().Trim()) + "_" + usernm.Trim() + "_" + DateTime.Now.ToString("yyyyMMdd_HHmmss").Trim();
      getExtension = System.IO.Path.GetExtension(uploadFile.FileName.ToString().Trim());

      string FilePath = Server.MapPath("~\\Upload\\" + nameFile + ".txt");
      string pathFile = Server.MapPath("~\\Upload\\");

      if (System.IO.File.Exists(FilePath))
      {
           System.IO.File.Delete(FilePath);                            
      }
      uploadFile.SaveAs(FilePath);//i think failed at this process
   }

In the Web.config file, i already set the configuration for maxRequestLength , executionTimeout, and maxAllowedContentLength. Maybe my code is wrong, can you guys give me the better way to upload such file? Thank You, Sorry for my bad english.

<system.web>
    <httpRuntime executionTimeout="3600" maxRequestLength="102400" 
     appRequestQueueLimit="100" requestLengthDiskThreshold="10024000"/>
</system.web>

executionTimeout : Specifies the maximum number of seconds that a request is allowed to execute before being automatically shut down by ASP.NET.

maxRequestLength : Specifies the limit for the input stream buffering threshold, in KB

appRequestQueueLimit : Specifies the maximum number of requests that ASP.NET queues for the application.

requestLengthDiskThreshold: Specifies the limit for the input stream buffering threshold, in bytes. This value should not exceed the maxRequestLength attribute.

Change these setting and see what happens. It also would be nice to know the version of IIS you are using. https://msdn.microsoft.com/en-us/library/e1f13641%28v=vs.100%29.aspx