When accessing the report server, avoid logging into Windows

We use Microsoft Reporting Service 2008 R2 to design reports, and we access these reports through the ASP application.

Response.Redirect(http://<serverIp>:80/ReportServer/Pages/ReportViewer.aspx?%2fReport+Project3%2fReport1&rs:Command=Render"n_Id=675);

When I access my report server via the web service URL, it asks for a Windows login and password when accessing from another computer (works fine if I provide credentials), but it works fine on the local computer. What configuration do I need to accept to get rid of this?