I have written code in Visual Studio.NET and used data from SQL Server 2008. After debugging, it says:

Login failed for user 'sunny'. 

When I try to set the user as something else, it keeps on reporting that error. I start sql with windows authentication and the username there is: sunny-lptp\sunny.

I do not have any sql authentication user/pass on sqlserver express 2008.

I tried changing the authentication in server/security tab. I changed it to both windows and sql. but it didn't fix the error.

What should I do?

Here is the connection string in web.config:


And the code:

scn = new sqlConnection(
  • 3
    Have you set Integrated Security=true; in your connection string ?
    – GX.
    Sep 20, 2012 at 15:31
  • 4
    Please show your Connection String. Sep 20, 2012 at 15:33
  • I have this for connection : scn = new sqlConnection(ConfigurationManager.AppSettings["SchoolsDBConnectionString"].ToString()); and this for connectionstring in web.config: 'code' <configuration> <appSettings> <add key="SchoolsDBConnectionString" value="server=sunny-lptp\sqlexpress;database=SchoolsDB;"></add> </appSettings>
    – SunnY
    Sep 20, 2012 at 17:01

2 Answers 2


Append on Trusted_Connection=True to the end of your connection string in your config file:


Great resource for connection strings


So I don't know integrated security or if that resolved your problem, however usually when I see a 'login failed' with a windows user, it has the whole username: "Domain\user". In your case it only states "Sunny" which might mean it's trying to use SQL Authentication.

Can you open up profiler and record 'failed logins' from your host and see what is going on? Let us know if it didn't work and we can dig deeper.

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