Login failed for user 'NT AUTHORITY\SYSTEM'.

[micky]

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?

 

[Patrick.O.Ige]

What does your ConnectionString look like?
Are you using integrated security?
Elaborate more..
Patrick

 

[micky]

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:\Inetpub\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~~