The Issue:
A 64-bit process can load only 64-bit components in it's process boundary. Same is true for a 32-bit process also. So, if your application is 64 bit, you will need a 64-bit provider or driver to connect to Microsoft Access (mdb, accdb) or Microsoft Excel 2010 (xls, xlsx, and xlsb) or text files. Bad news is that there is no 64-bit provider or driver available "yet" to connect to these file-based data sources. Good news is that a 64-bit Provider is heading your way which is currently in beta phase.
The Kludge:
The common workaround is to connect to a 32-bit SQL Server instance that has a Linked Server to the Access/Excel/Text file. This is a hack, can be difficult to get set-up, and can have stability and performance issues, and realistically, we at Microsoft would rather not support this setup or issues arising from it.
The Good news:
A 64-bit driver is headed your way. This is great news for users in a 64-bit world. Soon you'll be able to connect to these file-based data sources from your 64-bit application, rather than wrestle with obscure settings to force them to connect via a Linked Server.
The next version of Microsoft Office, Office 2010, will be available in a 64-bit version. This version will include a 64-bit version of "2010 Office System Driver Connectivity Components" which will include all the needed 64-bit ODBC driver and OLEDB providers to connect to these file-based data sources.
You will not have to buy or install Office 2010 to obtain and use the new 64-bit components. Like the current version of the provider, it will be available as a free download.
You can download the beta version from here:
http://www.microsoft.com/downloads/details.aspx?familyid=C06B8369-60DD-4B64-A44B-84B371EDE16D&displaylang=en
Connection string for 64-bit OLEDB Provider:
Connection string for 64-bit ODBC Driver:
The gotchas:
Authors: Enamul Khaleque & Srini Gajjela [DSD-SQLDeveloper group at Microsoft]