Deleted sql server windows authentication user
When you add a Windows Authentication login to SQL Server, the login gets created using the Windows Security ID, or SID, of the Windows user to create the login.  

The name of the login is irrelevant, since authentication occurs via the SID.

If you delete and re-create a Windows user that has a login in SQL Server, the newly created Windows user will have a different SID than the old user, and hence will not be linked to the SQL Server login.  In order to have the new Windows user login to SQL Server, you need to create a new SQL Server login for the user via the CREATE LOGIN T-SQL statement, as in:

CREATE LOGIN &lt;login_name&gt;
FROM WINDOWS;