Sql server does not exist or access denied

[yusufozkay]

I got this message when I try to run my asp.net web application on my computer. The code:
string baglan = "Data Source=localhost; Initial Catalog=Northwind; Integrated Security=SSPI";
SqlConnection vt_baglanti = new SqlConnection(baglan);
The error line is:
vt_baglanti.Open();

I couldn't find the problem.

[mmetzger]

Using Windows Authentication requires that the ASP.NET account has access to the SQL server. You need to either use impersonation or provide access to the ASP.NET account in SQL.