Hi, I have a custom assembly .dll file in C#. I have many methods and they work perfectly. I have also created a method to access database using Linq_to_SQL. If I create a sql server user (not in AD) and in <connection, ConnectionString of my c# method hard code the username and password, from report server have a connection to the database and my method will work. If I use a AD username that has the same right access on the database and place the username and password into the ConnectionString then it works. My questions is this? does the assembly code uses reporting services "services" user as authonication? In connectionString this is what I use <Connection Mode="AppSettings" ConnectionString="server=ServerName;database=DBName;Persist Security Info=False;Integrated Security=SSPI" SettingsObjectName="rptCustomAssembly.Properties.Settings" SettingsPropertyName="myDbConnectionString" Provider="System.Data.SqlClient" />