Error 27502 Could not coonect to Microsoft SQL Server. Provider cannot be found

Good afternoon,

I am attempting to install an AP system for a client.  While going through the install process it wants to connect to a SQL 2008 R2 instance.  I recieve the following:

Error 27502 Could not coonect to Microsoft SQL Server.  Provider cannot be found

I've done the steps below in an attempt to troubleshoot the issue:

1.  Ensured that Shared Memory, Named Pipes, and TCP/IP were enabled within 'SQL Server Configuratoin Manager'

2.  Windows Firewall (disabled within group policy)

3.  ODBC (created connection through interface and tested - success

4.  SQLCMD testing (TCP/IP, instance name, IP, TCP\IP port number) - success

5. Event logs are clean

6.  Database server entered as both (local\db and servername\db

Thank you an advanceAny ideas as to what is causing my issue?  

Other info:
Server 2003 (up to date on patches etc)
SQL Server 2008 R2 Express (up to date on patches etc)