I have a new instance of SQL Server 2008 RS Standard Edition. I enabled Mixed-Mode Authentication but I can't get Windows Authentication to work. I get the Error: 18456, Login Failed for user 'MyDomain\jreddy'. I can log in with the sa account so I can make changes, but I'm not sure what to change. Any help would be greatly appreciated.
I've checked the event log and found this error relating to the login failure:
Reason: Token-based server access validation failed with an infrastructure error.
Apparently the problem was with UAC on the Windows 2008 server. Our network guys were changing some group policies and turned UAC on for all our servers. So, this had nothing to do with switching edition of SQL Server (Ent --> Standard). Turning off UAC fixed the issue I was having.