Or else Use Microsoft JRO.

Add a reference to Microsoft Jet and Replication Objects 2.x Library by opening Project Menu. And then use this function
VB Code:
  1. Public Function compactRepairMDB(ByVal sourceMDBPath As String, ByVal targetMDBPath As String) As Boolean
  2.     Dim jetReplicationObject As JRO.JetEngine
  3.     Set jetReplicationObject = New JRO.JetEngine
  4.     jetReplicationObject.CompactDatabase _
  5.         "Provider=Microsoft.Jet.OleDB.4.0;Data Source=" _
  6.         & sourceMDBPath, "Provider=Microsoft.Jet.OleDB.4.0;Data Source=" _
  7.         & targetMDBPath
  8.     compactRepairMDB = True
  9.     Set jetReplicationObject = Nothing
  10.     Exit Function
  11. CompactErr:
  12.     compactRepairMDB = False
  13. End Function

You can use this function like this
VB Code:
  1. JetReplication.compactRepairMDB("C:\db1.mdb", "C:\db2.mdb")