After a database has been restored, users may become orphaned, or disconnected, from the database. You will see an entry for the user in the syslogins table (select * from syslogins;), but the user will not be able to sign onto the restored database. You have to clear these with the sp_change_users_login stored procedure.
Check for user disconnects or orphaned users by using the following SQL script:
-- Search for orphans using the following user report use [Database Name] go sp_change_users_login 'report' go
Attach the orphaned users:
-- If there are orphans, clear them with the following script sp_change_users_login 'update_one', 'User Name', 'User Name' go
