Please follow the below code for ASP.Net and modify same code for WINforms
Server path:
<add key="ReportServerUrl" value="http://Local/ReportServer"/>
<add key="ReportServerFolder" value="/Reports/"/>
<add key="ReportServerUser" value="User"/>
<add key="ReportServerPass" value="Password"/>
<add key="ReportServerDomain" value="ServerIP"/>
Getting Path :
ReportServer = ConfigurationManager.AppSettings["ReportServerUrl"].ToString();
UserName = ConfigurationManager.AppSettings["ReportServerUser"].ToString();
Password = ConfigurationManager.AppSettings["ReportServerPass"].ToString();
ReportDomain = ConfigurationManager.AppSettings["ReportServerDomain"].ToString();
ReportServerFolder = ConfigurationManager.AppSettings["ReportServerFolder"].ToString();
rptViewer.ProcessingMode = ProcessingMode.Remote;
rptViewer.ServerReport.ReportServerUrl = new Uri(ReportServer);
rptViewer.ServerReport.ReportPath = ReportServerFolder + "RptGENERAL.rdl";