Microsoft ODBC Administrator Error

I am getting an error in the ODBC Administrator when I try to add a microsoft access (.mdb) System DSN source. Microsoft access is not an option for me and when I click on anything it give me the following error:

The setup routines for the Microsoft Access Driver (*.mdb) ODBC driver could not be found. Please reinstall the driver"

OK - fine - but I can't find the driver to reinstall it! When I try to reinstall access it says that there is no entry in the registry and wants me to cancel, retry or ignore.

If someone can help me I would really appreciate it!

Thanks

Deb