Access 2.0/earlier can't open 7.0 .mdb or .mdw files due to design.

Cause:

This problem occurs because Access 7.0 has a new .MDB file structure that is different from Access 2.0 and earlier, and uses entries in the Windows 95 registry, rather than the initialization file, to store the locations and names of workgroup system files. This is by design of Microsoft Access 7.0.

Solution:

There is no workaround to this problem. Also, do not convert any existing or shared Access 2.0 databases (.MDB and .MDA files) to Access 7.0 unless the databases do not need to be opened with Access 2.0, or unless all users of the databases have upgraded to Access 7.0.