Hello! I am new to this forum and a nubie to MS SQL

I installed SQL Server 2008 R2 standard edition version 10.50.1600.1 in February of 2013, but never used it because other software packages I installed used their own SQL Server instances, typically SQL 2005 express. Now it is time to install software that will use MS SQL and I find that I can't connect to it to do any necessary configuration. SQL Server Management studio can connect to the instance of SQL 2005 express.  

MS SQL 2008 R2 is running under the 64 bit version of MS Server 2008 R2 [RTM], SP1, Ver 6.1 (7601). I have 24GB of memory in a fast ASUS server.

The server is the single domain controller. I know, not recommended, but I don't want to add another server to the domain. 

I checked SQL server configuration manager and found all services running with the logon as the domain server's administrator account (DSAA). The running services are: SQL Server (MSSQLSERVER), SQL Server Agent (MSSQLSERVER), SQL Server Browser, SQL Server Reporting services, SQL Full-text fiiter Daemon Launcher (MSSQLSERVER), SQL Server Analysis Services (default) and SQL Server Integration Services 10.0.  The protocols (shared memory, named pipes and TCP/IP) are all enabled. The same protocols are enabled for the clients. 

The logon that I thought I used for SQL Management Studio is also the DSAA. I say "that I thought I used because that is what is in my notes from 2013.

Despite the fact that the services seem to start using the DSAA logon, when I try to log on to management studio I get this error message:

A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 25 - Connection string is not valid) (.Net SqlClient Data Provider)

Also, when I  look at the logs for any recent date, the following error recurs with a frequency of 1 minute after initial housekeeping:

Error: 18456, Severity: 14, State: 11

Login failed for user '<domain>\<DSAA name>'. Reason: Token based server access validation failed with an infrastructure error. Check for previous errors. [CLIENT: <local machine>]

My authentication mode is "mixed" and my database name is 'master'

Any help that can be provided is much appreciated.

Hello again!

This is an 8/28/15 update to my post from yesterday.

Nag'a' came to the same conclusion that I did as far as state 11 is concerned e.g. the authentication was successful but.... Sometimes I just can't let go so... 

I went back to the "beginning of time" for this server (only three years) and collected user names and corresponding passwords and tried every combination in windows and SQL authentication. None worked. So the username/password issue is not the issue and I'm not nuts....well maybe a little at this point... 

I got completely frustrated trying to connect to the existing server, so I created another instance, using the same username and password for all but one service. SSMS connected instantly to the new instance, but as a network server. So the question about being able to use the same username and password for everything is now answered.

However, I'm not clear on what determines whether an instance gets installed as a network or local instance. I don't remember any selections to that effect.

Any Ideas?

Thanks again..

• Edited by FirstPhilbert 10 hours 45 minutes ago

Thanks for your reply VMID. The account is enabled, not locked, expired or disabled. I have te password set to never expires for now. 

Thanks for your reply Kumar. I renamed the built-in account for Windows Server, then use that account as a system logon and SQL Server logon. All of the services start successfully with those credentials. Is it possible that using the same credential for the system, SQL and the SQL services is causing the problem?

Thanks for your reply Simon. I tried running SSMS as administrator to no avail. I am already running under an account that has system, SQL and domain admin privileges. I haven't tried disabling UAC yet. I did attempt to connect using only the system server name and the following message appeared:

A connection was successfully established with the server, but then an error occurred during the login process. (provider: Shared Memory Provider, error: 0 - No process is on the other end of the pipe.) (Microsoft SQL Server, Error: 233)

Another forum suggested that might be due to a missing database selection, but I did have the associated database "master" selected. 

Yesterday I ran the command SQLCMD -L on the command line to identify all running servers and it came back with the physical <server name> as one and <server name\BKUPEXEC> as a second. Since I installed SQL using the default server, <MSSQLSERVER> I would have thought that  <MSSQLSERVER> would appear in the list.