I had to create an ODBC datasource for an access database on my Windows 7 machine and for some reason the *.mdb driver doesn't show up in the control panel ODBC administrator.
After much swearing and google-ing I found the solution.
In C:\windows\sysWOW64 there is an executable called odbcad32.exe. You need to run this exe as administrator to gain access to all the ODBC drivers that come with Microsoft Office, etc.
Thanks Microsoft for another fine product!