xp_grantlogin (Transact-SQL)
Applies to: 
SQL Server
Grants a Windows group or user access to SQL Server.
Important
This feature will be removed in a future version of SQL Server. Avoid using this feature in new development work, and plan to modify applications that currently use this feature. Use CREATE LOGIN instead.
Transact-SQL syntax conventions
Syntax
xp_grantlogin { [ @loginame = ] 'login' } [ , [ @logintype = ] 'logintype' ]
Arguments
[ @loginame = ] 'login'
The name of the Windows user or group to be added. The Windows user or group must be qualified with a Windows domain name in the form <domain>\<user>. @loginame is sysname, with no default.
[ @logintype = ] 'logintype'
The security level of the login being granted access. @logintype is varchar(5), with a default of NULL. Only admin can be specified. If admin is specified, @loginame is granted access to SQL Server, and added as a member of the sysadmin fixed server role.
Return code values
0 (success) or 1 (failure).
Remarks
xp_grantlogin is a system stored procedure instead of an extended stored procedure. xp_grantlogin calls sp_grantlogin and sp_addsrvrolemember.
Permissions
Requires membership in the securityadmin fixed server role. Changing the @logintype requires membership in the sysadmin fixed server role.