It sounds as if you're trying to use a 32 bit driver/
From MS:
"
If you use the 64-bit odbcad32.exe to configure or remove a DSN that connects to a 32-bit driver, for example, Driver do Microsoft Access (*.mdb), you will receive the following error message:
The specified DSN contains an architecture mismatch between the Driver and Application

To resolve this error, use the 32-bit odbcad32.exe to configure or remove the DSN."

If this OBDC connects to a VFP datasouce, you must use the 32 bit driver.