This type of stuff drives me nuts. I'm having trouble finding the exact issue that I'm having, maybe I just don't know the terminology. Anyway, I had a working website using MVC and Entity Framework, but then I coded an error in a partial view page (ascx). Then all of a sudden I started to get this message.

Cannot open user default database. Login failed. Login failed for user 'NT AUTHORITY\SYSTEM'

I've found plenty of suggestions about opening SQL Server Management Studio, Double Click on Security, Double Click on Logins, Double click on NT AUTHORITY\SYSTEM and then double click on User Mapping. In this view I'm suppose to check the box for my database so that this user is mapped to this login. However, since I created my database in Visio Studio 2008 as part of my solution, it doesn't show up to allow me to click on it. So what do I do now?

What drives me nuts is that everything was working fine. I was using my computer name to access the website and everything was working fine until the coding error. I've fix the error but still getting the error. I should also mention that this error started yesterday too around the same time but later cleared itself up. If I use localhost to access the site, it works just fine.

IIS7 configuration for my website:

Application Pool = DefaultAppPool
Physical Path Credentials Logon = ClearText

With in connection strings. I do see the one for my database in this solution. Entry Type is local

metadata=res://*/Models.DataModel.csdl|res://*/Models.DataModel.ssdl|res://*/Models.DataModel.msl;
provider=System.Data.SqlClient;
provider connection string="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\FFBall.mdf;Integrated Security=True;User Instance=True;MultipleActiveResultSets=True"

And somewhere I remember changing the identity from Network Service to LocalSystem. Because when I first stared I was getting this same message, but I changed this value and it started working. I saw that suggested somewhere too but I do not recall. Wait I remember now, I believe in IIS7, under Application Pools, DefaultAppPool identity is set to LocalSystem.

Additional things I've tried.

• Restart the computer
• Recycle the application pool.
• Antivirus isn't running.

Any help would be appreciated.

Thank you in advance.