Login failed for user 'NT AUTHORITY\SYSTEM'.

i use database in app_Data ...*.mdf file not using sql server ..
when i open the database file on visual studio 2005 there is error occur
like below.
========================================
===================
Cannot open user default database. Login failed.
Login failed for user 'NT AUTHORITY\SYSTEM'.
========================================
====================
and ... when i access website that using the database visual studio 2005 can
not open the database file
how should i solve this problem' i don't know why?What does your ConnectionString look like?
Are you using integrated security?
Elaborate more..
Patrick
"micky" <somequestion@.gmail.com> wrote in message
news:uPm9UWc$FHA.1148@.TK2MSFTNGP10.phx.gbl...
> i use database in app_Data ...*.mdf file not using sql server ..
> when i open the database file on visual studio 2005 there is error occur
> like below.
> ========================================
===================
> Cannot open user default database. Login failed.
> Login failed for user 'NT AUTHORITY\SYSTEM'.
> ========================================
====================
> and ... when i access website that using the database visual studio 2005
can
> not open the database file
> how should i solve this problem' i don't know why?
>
my website consist of three wesite in a solution.
http://localhost/solution/
-App_Data/db.mdf
-a(http://localhost/a/)
-b(http://localhost/b/)
-c(http://localhost/c/)
a,b,c sites are using db.mdf file in app_data folder of solution project
so i made connection string like below.
<add name="ConnectionString" connectionString="Data
Source=.\SQLExpress;Integrated Security=True;User
Instance=True;AttachDBFilename=C:\Inetpu
b\wwwroot\Solution\App_Data\db.mdf"
providerName="System.Data.SqlClient" />
the problem is ...
open a,b or c website and then i also open vs2005 to modify database
error occur to me...like Unc share...
in opposite , it will be same result ...
help me~~
"Patrick.O.Ige" <naijacoder@.hotmail.com> wrote in message
news:eCqdB6t$FHA.3568@.TK2MSFTNGP09.phx.gbl...
> What does your ConnectionString look like?
> Are you using integrated security?
> Elaborate more..
> Patrick
> "micky" <somequestion@.gmail.com> wrote in message
> news:uPm9UWc$FHA.1148@.TK2MSFTNGP10.phx.gbl...
> can
>