Can not find 'NT AUTHORITY\NETWORK SERVICE'. on Sql Server 2012 Hi How﻿ do i fix this Error?
when i run my MVC app i get this error
though my web.config is find. the error is on my DB call Sample:

Cannot open database "Sample" requested by the login. The login failed.
Login failed for user 'NT AUTHORITY\NETWORK SERVICE'.

Also cannot find ‘NT AUTHORITY\NETWORK SERVICE’. on my sql server management studio 2012 object explorer under Security > Logins﻿ to right click and set the Properties.

How can i add it, is this a win vista issue ?
You can't find the NT AUTHORITY\NETWORK SERVICE because it hasn't been added. You need to explicitly add it.

Goto Security-> Logins (in SSMS) and add that user.  Then go to your database and add as a login with relevant permissions.

Better still, script it:

CREATE LOGIN

CREATE USER