SQL Server 2008: The login is from an untrusted domain and cannot be used with Windows authentication The question here is different from 1 &amp; 2

When trying to connect to a SQL Server database that is on another system in the network both are in workgroup, when attempting to connect to a SQL Server 2008 instance using SQL Server Management Studio with Windows authentication, I get connected.

But when trying to connect from my application, I get the following error


  (Login failed. The login is from an untrusted domain and cannot be
  used with Windows authentication.) Native=18452).


If SQL Server Management Studio can connect, what would be required for my application to get connected?
If you are using Windows 7, you might have to "run as administrator".  This will allow the app to reuse your windows credentials and pass them to the SQL Server.  Otherwise, you will pass guest credentials to the SQL Server.