The process cannot access the file because it is being used by another process. at line "FileIO.FileSystem.RenameFile ("c:\Arjuonsoftshield\security.mdb"; "security.sys")

Public Sub expass()
        If FileIO.FileSystem.DirectoryExists("c:\Arjuonsoftshield") Then
            FileIO.FileSystem.FileExists("c:\Arjuonsoftshield\security.sys")
            FileIO.FileSystem.DeleteFile("c:\Arjuonsoftshield\security.sys")
            Dim databaseName As String = "c:\Arjuonsoftshield\security.mdb"
            Dim tableName As String = "KEYS"
            Dim cat As ADOX.Catalog = New ADOX.Catalog()
            cat.Create("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & databaseName & ";Jet OLEDB:Engine Type=5;Jet OLEDB:Database Password=123;")
            cat = Nothing
            Dim con As New OleDb.OleDbConnection("PROVIDER=Microsoft.Jet.OLEDB.4.0;Jet OLEDB:Database Password=123;Data Source =" & databaseName)
            con.Open()
            Dim cmd As New OleDb.OleDbCommand("CREATE TABLE [" + tableName + "] ([Field1] TEXT(10), [Field2] TEXT(10))", con)
            cmd.ExecuteNonQuery()
            MessageBox.Show("Exported Successfully")
            con.Close()
            con.Dispose()
            System.GC.Collect()
            FileIO.FileSystem.RenameFile("c:\Arjuonsoftshield\security.mdb", "security.sys")
        Else
            FileIO.FileSystem.CreateDirectory("c:\Arjuonsoftshield")
            Dim databaseName As String = "c:\Arjuonsoftshield\security.mdb"
            Dim tableName As String = "KEYS"
            Dim cat As ADOX.Catalog = New ADOX.Catalog()
            cat.Create("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & databaseName & ";Jet OLEDB:Engine Type=5;Jet OLEDB:Database Password=123;")
            cat = Nothing
            Dim con As New OleDb.OleDbConnection("PROVIDER=Microsoft.Jet.OLEDB.4.0;Jet OLEDB:Database Password=123;Data Source =" & databaseName)
            con.Open()
            Dim cmd As New OleDb.OleDbCommand("CREATE TABLE [" + tableName + "] ([Field1] TEXT(10), [Field2] TEXT(10))", con)
            cmd.ExecuteNonQuery()
            MessageBox.Show("Exported Successfully")
            con.Close()
            con.Dispose()
            System.GC.Collect()
            FileIO.FileSystem.RenameFile("c:\Arjuonsoftshield\security.mdb", "security.sys")
        End If
    End Sub