Dim delvnuk As String
Dim rsdelvnuk As ADODB.Recordset
Dim t As String
Dim q As Integer

Dim pp As String
Dim rspp As ADODB.Recordset

delvnuk = "select Текст27,TaskID from Tasks"
Set rsdelvnuk = conn.Execute(delvnuk)

Do While Not (rsdelvnuk.EOF Or rsdelvnuk.BOF)
    t = rsdelvnuk.Fields( 0 ).Value
    If t <> "РИ" Then q = rsdelvnuk.Fields( 1 ).Value
    pp = "DELETE * FROM Tasks WHERE TaskID Not In (SELECT TaskID FROM Tasks WHERE TaskID=" & q & " or ParentID=" & q & ")"
    Set rspp = conn.Execute(pp)
    rsdelvnuk.MoveNext
Loop

select *  from Tasks where ParentID in (select TaskID  from Tasks where ParentID in (SELECT  TaskID  FROM Tasks where Текст27<>"РИ"))