I have MS VS 2010 installed on my Windows 7 but, I don't have the SQL Server Native client installed in it.
After loading Visual Studio I do click menu Data / Transact-SQL Editor / New Query Connection.
The SQL Server 2008 R2 login dialog will show up, I type server name, select SQL Server authentication, type username and password and click connect. The connection is established and an editor window shows up and I'm ready to query!
I understand the SQL Server 2008 native client files are sqlncli10.dll, sqlnclir10.rll. I did search for these files in my entire hard drive and they weren't found.
So, how is Visual Studio 2010 connecting to SQL Server 2008 if I don't have the native client installed?
Is VS 2010, when connecting to SQL Server 2008, using .NET Framework assemblies?
If NO native client is installed, Visual Studio 2010 is using the .NET Framework version 4.0 to connect to SQL Server 2008 R2 when connecting through menu Data/Transact-SQL Editor/New Query Connection.
I verified and it is loading assembly System.Data.dll (located under C:\Windows\Microsoft.NET\Framework\v4.0.30319) to establish the connection to the server.
I have not installed the Native client 10.0 for SQL Server 2008 R2 and I'm not using it right now but, if installed, the native client files (sqlncli10.dll, sqlnclir10.rll, and s10ch_sqlncli.chm) should be found under
%SYSTEMROOT%\system32\
which are installed as part of the SQL Server installation.
There is also a redistributable installation program named sqlncli.msi, which should be found on the SQL Server installation CD under
%CD%\Setup\
The reference for installation details
http://msdn.microsoft.com/en-us/library/ms131321.aspx
And the reference for the SQL Server 2008 R2 Native Client Features