Are you asking how to determine all of the reference libraries installed on
a given machine, or whether a referenced library actually exists?
For the former, you'd have to query the registry (and it's a non-trivial
exercise)
For the latter, you can check whether any of the Reference elements in the
References collection have their IsBroken property set. From the Help file:
Sub ReferenceProperties()
Dim ref As Reference
' Enumerate through References collection.
For Each ref In References
' Check IsBroken property.
If ref.IsBroken = False Then
Debug.Print "Name: ", ref.Name
Debug.Print "FullPath: ", ref.FullPath
Debug.Print "Version: ", ref.Major & "." & ref.Minor
Else
Debug.Print "GUIDs of broken references:"
Debug.Print ref.GUID
EndIf
Next ref
End Sub
(Note that if the IsBroken property is True, Access generates an error if
you try to read the Name or FullPath properties.)