Can't create Windows Login's on a case sensitive SQL Server 2005 Instance - MSG 15401 I need to create 3 logins on a SQL Server 2005 instance:


DOMAIN\aaa
DOMAIN\bbb
DOMAIN\ccc


However two of them (aaa and bbb) fail with the following error:


  Msg 15401, Level 16, State 1, Line 5 Windows NT user or group
  'DOMAIN\aaa' not found. Check the name again.


When I try to add them with DOMAIN\AAA and DOMAIN\BBB it works. 

What is causing this strange case sensitive behaviour? And how can I add all accounts
lower case?

I found a KB article from Microsoft for the 15401 error, but nothing in there explains this behaviour.
You chose a case sensitive collation when installing SQL Server

You will have "CS" in this result:

 SELECT SERVERPROPERTY('Collation')


You either live with it or rebuild the master database