This article was previously published under Q245768
When you add an existing Windows NT logon account as a Microsoft SQL Server login, you receive the following error message:
Error 15401 Windows NT user or group 'Domain_name\User_name' not found. Check the name again.
This problem occurs because you install SQL Server by using a case-sensitive Unicode collating sequence.
You can add this new login in SQL Server by typing the user name or group name exactly as it is entered in User Manager for Domains. (This includes using the original case for every letter.) You can copy this name from the User Manager for Domains to SQL Server Enterprise Manager.
This behavior is linked only to Unicode case sensitivity. This behavior does not occur if you only modify the sort order.
Steps to Reproduce the Problem
Install SQL Server by using a case-sensitive collating sequence for Unicode. Make sure that you click to clear the Case Sensitive check box next to the Unicode Locale Identifier list box.
Use the Windows NT User Manager for Domains to create a new user that is named Domain_name\Test. Type this user name by using both uppercase and lowercase letters.
Note In this user name, Domain_name represents the actual domain name.
In SQL Server Enterprise Manager, right-click the Logins icon in the Security folder, and then click New Login on the shortcut menu.
In the Name dialog box, type the user name that you created in step 2. For example, type the following:
Make sure that you type this user name by using only uppercase letters. By doing this, you receive the following error message:
Error 15401 Windows NT user or Group 'Domain_name\TEST' not found. Check the name again.
In Query Analyzer, run the following query:
exec master..sp_grantlogin '<Domain_name>\TEST'
When you run this query, you receive the following error message:
Server: Msg 15401, Level 11, State 1, procedure sp_grantlogin, Line 36 Windows NT user or Group 'Domain_name\TEST' not found. Check the name again.