Topics from the Microsoft SQL Server Protocols team - Netlibs, TDS, SQL Browser, etc.
Our colleagues over in the SQL Server Security team have developed an open tool for troubleshooting "Login Failure" errors. If you're having an issue with "Login Failure" errors and can't resolve it from the other SQL Protocols blog articles here, check out their blog post and give their tool a try: http://blogs.msdn.com/sqlsecurity/archive/2010/03/29/sql-server-authentication-troubleshooter.aspx
Dan BenediktsonSQL Server Protocols
Disclaimer: This posting is provided "AS IS" with no warranties, and confers no rights
I get the following message:
CCon: open connection on Line 0
Error (-2147467259) Named Pipes Provider
Could not open a Connection on Sql Server 
I got this message when updating ACT by Sage database
HResult 0x15, Level 16, State 1
Encryption not supported on the client.
Sqlcmd: Error: Microsoft SQL Native Client : Client unable to establish connection.
Sqlcmd: Error: Microsoft SQL Native Client : An error has occurred while establishing a connection to the server. When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections..
To get more information about Isolation levels in SQL Server including Locks and its impact on database in detail with examples, refer the below link: