Fix : Error : Error 15401: Windows NT user or group ‘username’ not found. Check the name again.
This is quite a famous error and I was asked to write about it by couple of readers. The reason I was not writing about this as the solution of this error is very well explained in Book On Line. All the potential causes and their solutions are explained well here. This post/article should be considered as book mark to solution.
Fix/WorkAround/Solution:
Refere Microsoft Help and Support : How to troubleshoot error 15401
Reference : Pinal Dave (http://blog.SQLAuthority.com)




pls slove this error
Windows NT user or group ‘username’ not found. Check the name again.
Hi,
I have one suggestion, now that it works for me.
I was unable to add a new login for a local windows user on a local sql server just because of case.
The Sql Server management studio process would always give my user login like this : AMITY\Dave.
In fact, the right case is Amity\Dave.
By executing sp_grantlogin “Amity\Dave” it worked fine.
Bad GUI tools don’t ease the use at all.
David
Hi Pinal,
I got this err when I tried to manually change the Window group name after the physical server got renamed.
After renaming the server, I use sp_dropserver and sp_addserver to bring SQL in sync with the new server name. Then I restart SQL Server. Everything seems to work fine. However, under Security -> Logins there are 3 groups that are prefixed by the old server name and also contain the old server name within their name (for example: oldservername\SQLServer2005SQLAgentUser$oldservername$MSSQLSERVER)
Can you please advise how to fix it?
I found out lots of useful information from your website.
Thank you very much for your help!
Alice
Hi, I am a new SQL server 2008 user. I like to add another user to existing window user service account in sql server 2008. as example I have a account on my name and want another account with different name. Please help.
Thanks.
Sunil