If you have an old VB6 (Visual Basic 6) application that uses SQL Native Client via ADO for connecting to Microsoft SQL Server you must be aware that Native Client dll discontinues the name from SQL 2005 to SQL 2008. Therefore the application raises the error: Provider cannot be found may not be properly installed.
Here is the link: http://msdn.microsoft.com/en-us/library/ms131291.aspx. The Sqlncli.dll becomes Sqlncli10.dll, this means that you should recompile VB6 or, better, install also the Native Client package for 2005: http://www.microsoft.com/downloads/en/details.aspx?FamilyID=d09c1d60-a13c-4479-9b91-9e8b9d835cdc&displaylang=en (Microsoft SQL Server Native Client).
If you find out other solutions or this solution doesn’t work for you please left a comment!
Isola Software 
Hey
I have the same problem that when im tried to remote SQLServer 2008 by VB.Net i get this msg (provider cannot be found. it may not be properly installed)
but when im tried to connect by another PC there’s no problem
i hope to find resolve to this problem 🙂
Is the native client installed on both machine?
hey mr giulioroggero
im uploaded it on host (www.somee.com)
and the native client is installed on my pc
thanx for reply …