what is the best driver for SQL

Personally I use SQLOLEDB. The MSDASQL provider still uses OLE DB, but I believe it also uses the ODBC driver. Obviously this causes overhead, but it also requires ODBC to be installed on the host machine. OLE DB is a newer technology, use it if you can.

If you application is to use only MS-SQL then your best bet would be to use ADO.

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/adosql/adoprg01_1kwv.asp

Check out this and many other documents at msdn.com

The ADO.NET SqlClient is the fastest and most efficient way to access Sql Server datastores.

The MSDASQL provider is a ODBC provider and is considered to be obsolete by Microsoft. (see http://msdn.microsoft.com/library/default.asp?url=/library/en-us/mdacsdk/htm/mdac_deprecated_components.asp)
The native OLE DB driver will give you superior performance over a ODBC driver. For a VB6 app using ADO the SQLOLEDB provider is your best choice.

SQLOLEDB is the best.
example:
dim con as new ADODB.Connection
dim str as strong

con.provider = "SQLOLEDB"
con.open "Server=your_server";Database=your_database";Trusted_connection=yes"

see its simple

SQLOLEDB is the best.
example:
dim con as new ADODB.Connection
dim str as strong

con.provider = "SQLOLEDB"
con.open "Server=your_server";Database=your_database";Trusted_connection=yes"

see its simple

ADO uses OLEDB providers to access data. There are many providers for many databases. For SQL Server, you basically have two options:
1. SQL Server OLEDB Provider (SQLOLEDB)
2. ODBC driver (MSDASQL)
ODBC is an older technology than ADO (although it has many similar goals).
For more efficient access, the SQLOLEDB provider is recommended.
The default provider is ODBC (MSDASQL). This is what is being used in your old connection string. When you use ODBC, you must specify either a DSN (data source name) or a driver, server etc.
In summary, you were using ODBC, but you should use OLEDB provider.
Hope these help...

MSDASQL is the OLE-DB Provider for ODBC.
ODBC is slow and you have to go through two layers: OLE-DB and then ODBC making things real slow.
SQLOLEDB is the native OLE-DB driver for SQL Server making it much more efficient.
ADO uses OLE-DB as a low level database access method.