Could not connect to server as sa.

[atheis]

I am running sugarcrm 5.1.0b for for more that one year. Today I wanted to login and got the following browser message:

Could not connect to server MYSUGAR as sa.

trying just to connect with sqlcmd to database gives the message:

HResult 0x2, Level 16, State 1
Named Pipes Provider: Could not open a connection to SQL Server [2].
Sqlcmd: Error: Microsoft SQL Native Client : An error has occurred while establi
shing a connection to the server. When connecting to SQL Server 2005, this failu
re may be caused by the fact that under the default settings SQL Server does not
allow remote connections..
Sqlcmd: Error: Microsoft SQL Native Client : Login timeout expired.

I restarted the whole system but nothing changed. I didn't change the running system so I am wondering why it doesn't work anymore.

I searched google and found the following explanation:

Could not open a connection to SQL Server [2] means:

winerr 2 means "The system cannot find the file specified". This error message means the client can reach the server but there is no Named Pipe listener with specific pipe name on the target machine. It also means the account can have a file sharing session without a problem.Possible reasons are:
a) typo in instance name or wrong instance name. The instance name is not the one you are targeting. Note that for default instance, you shouldn't use MSSQLSERVER as instance name.
b) Target SQL Server is not running
c) Named Pipe is not enabled on the server. In this case, the SQL server is not listenning on the specific pipe name.

What can I do now?

[atheis]

hostname of virtual machine was changed some days before..

renaming to old hostname solved the problem