SQL Server admin

[DD]

During the SQL installation,using the Mixed Mode, we ceated a windows login
sqladmin and added this windows login id in the Specify SQL Server
administrator also this id also added have permission for analysis
service.for some reason,

the id sqladmin need to be deleted from the windows, what is the impact of
deleting this login id from SQL LOGIN ? Can replace this login id with sa
login id ?

In SQL logins, there is BUILTIN\Administrators , is this refer to windows
builtin administrator group ?

we are installation the sql in mixed mode, but we do not want to allow to
use MS windows authentication to connect to any of the database ? can I
remove all the MS windows id from SQL login, by doing that , does it mean
that we can't use the MS authentication to connect the db ?

[Erland Sommarskog]

I'm not really sure what you really are trying to do, but yes, you
can drop all Windows logins from SQL Server and thereby use SQL Server
authentication only. Make sure that when you run

SELECT * FROM sys.server_principals

there is nothing with WINDOWS in the type_desc column.

I like to add that this is nothing I would recommend. Windows
authentication is usually to prefer.

...but there is still one loophole: you can't start the server in
single-user mode, and now you can log in with Windows authenticator
if you are an Windows admin. Handy if you have lost the sa password.

--
Erland Sommarskog, SQL Server MVP, esq...@sommarskog.se

Links for SQL Server Books Online:
SQL 2008: http://msdn.microsoft.com/en-us/sqlserver/cc514207.aspx
SQL 2005: http://msdn.microsoft.com/en-us/sqlserver/bb895970.aspx
SQL 2000: http://www.microsoft.com/sql/prodinfo/previousversions/books.mspx