Sub test()
Dim Nb As Boolean, Nb1 As Boolean, Nb2 As Boolean
Nb = Application.WorksheetFunction.CountIf(Range("C:C"), ComboBox2.Value > 1)
Nb1 = Application.WorksheetFunction.CountIf(Range("F:F"), Clng( DTPicker1) > 1)
Nb2 = Application.WorksheetFunction.CountIf(Range("n:n"), 'TexTbox4.Value > 1)
If Nb And Nb1 And Nb2 = True Then
MsgBox "Ok ça marche"
Exit Sub
End If
End Sub