If you are making a Windows Forms application there is 2 methods;
a) Use a network share that will always be accessible - you could alternatively use a fixed location such as
c:\Reports
b)Move your reports folder to the folder where the executable is and then use either;
rpt.Load(System.Windows.Forms.Application.StartupPath + "\\Reports\\ReportName.rpt");
or
rpt.Load(System.AppDomain.BaseDirectory + "\\Reports\\ReportName.rpt");
If you are making a ASP.Net application then you would create a Reports folder within your website (typically as a sub folder in the root of your web site) and then load the report using
rpt.Load(Server.MapPath(@"~/Reports/ReportName.rpt"));
Kind Regards