If you go to the DLL Help Database at
http://support.microsoft.com/dllhelp/
and do a search for dao360.dll, you'll find it not only comes with Office,
but with most of the newer operating systems. Since it's used in many
different places, it gets installed under Common Files/Microsoft Shared,
just like such other components as the Equation editor and the Proofing
tools.
Is your VB code actually running on the server (eg. by a service)? If so,
then yes, you will need DLLs to be registered on the server. If, however,
your code is on the server, but it's being run from a workstation, the DLLs
only need to be registered on the workstation.
You can also use ADO recordsets, but if you're strictly going against a Jet
database (i.e. an MDB file), DAO is probably better.